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QP514.R13  Clinical  chemistry; 


iL^ 


CI  IMIIIA    INIVKksriY 
I'AklMI-Nr     OK      I'HVSIOI.Oi.N 
IK     loHN    i;.   CURTIS    I.IIJRAHN 


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MANUALS 


Students  of  Medicine. 


CLINICAL 


CHEMISTKT 


AN    ACCOUNT   OF   THE 

ANALYSIS  OF  BLOOD,  UKINE,  MORBID  PRODUCTS,  ETC. 

WITH   AN   EXPLANATION   OF   SOME   OF   THE 

CHEMICAL   CHANGES   THAT    OCCUR  IN 

THE  BODY,   IN  DISEASE. 


CHARLES     HENEY     RALFE, 

M.A.,    M.D.,    CANTAJ)., 

FELLOW    OP    THE     ROYAL    COLLEGE    OF    PHYSICIANS,     LONDON  ;     ASSISTANT 

PHYSICIAN   AT  THE   LONDON   HOSPITAL;     FORMERLY    DKMONbTRATOR 

OF   PHYSIOLOGICAL   CHEMISTRY   IN   THE    MEDICAL   SCHOOL   OF 

ST.   GEORGE'S    HOSPITAL. 


ILLUSTRATED    WITH    16    ENGRAVINGS. 


HENRY    C.    LEA'S    SON    &    CO, 
FHILALELPHIA,    FA. 


SIR     ANDREW     CLARK,    Bakt., 

LL.D.,   M.D.,   ETC.,   ETC., 

Senior  Physician  of  the  London  Hospital, 

THIS  WOEK  IS   DEDICATED 

AS  A   SLIGHT  ACKNOWLEDGMENT  OF  THE  MANY  VALUABLE 

SERVICES  RENDERED   BY  HIM 

TO   THE 

MEDICAL  SCHOOL  OF  THE  LONDON   HOSPITAL. 


PEEEACE. 


This  work,  as  its  title  implies,  lias  been  written 
for  a  practical  purpose,  viz.,  to  furnish  students  and 
practitioners  with  a  concise  account  of  the  best 
methods  of  examining  chemically,  abnormal  blood, 
urine,  morbid  products,  etc.,  at  the  bedside  or  in  the 
hospital  laboratory.  It  has  been  purposely  made  as 
simj^le  as  possible. 

In  spite  of  the  disi^aragements  of  such  eminent 
clinical  teachers  as  Gra\'es  and  Trousseau,  chemistry 
has  become  more  and  more  important  to  the  physician 
as  a  means  of  elucidating  many  pathological  con- 
ditions, or  of  determining  the  character  of  the  morbid 
changes  effected  in  tissues  or  secretions.  Indeed,  it  is 
becoming  more  and  more  evident  that  we  must 
eventually  look  to  Chemistry  for  information  with 
regard  to  the  primary  alterations  that  occur  in  fluids 
and  tissues,  and  which  are  the  first  step  in  every 
disease.  But  even  if  original  investigation  iia  this 
direction  is  not  engaged  in,  the  student  or  prac- 
titioner will  find  that  by  making  a  chemical  exami- 
nation of  the  secretions,  abnormal  products,  etc.,  when- 
ever he  has  an  opportunity,  he  gains  such  considerable 


viii  Clinical  Chemistry. 

insiglit  into  the  nature  of  the  morbid  processes  p)*o- 
ducing  them,  as  enables  him  more  effectually  to 
comprehend  their  nature  and  modify  their  ill  efiects. 

As  few  medical  schools  are  now  without  physio- 
logical and  chemical  laboratories,  in  which  students 
can  obtain  the  necessary  manipulative  skill,  I  have  not 
cumbered  the  text  with  minute  directions  with  i-egard 
to  apparatus,  or  with  instructions  for  the  conduct  of 
such  simple  operations  as  weighing,  evaporation,  fil- 
tering, drying  precipitates,  etc.,  as  the  students  to 
whom  this  work  is  addressed  will  have  already  gone 
tlj rough  a  course  of  practical  training.  Those,  however, 
who  have  not  done  so  will  find  the  necessary  instruC' 
tions  in  my  work,  "  Demonstrations  in  Physiological 
Chemistry,"  which  I  wrote  for  the  purpose  of  instruct- 
ing second-year  students  in  the  practical  operations  of 
the  laboratory. 

London,  September,  lSb3. 


CONTENTS 


CHAPTER   I.  ^^^.^ 

PAGE 

Section  A.-Organic  Coxstitukxts  of  the  Animal  Body       1 
Skgtion  B.-Inorganic    Constituents    of    the   Animal 
Body ' 

CHAPTER  II. 
Section  A.-Chemical    Reactions    ok     Chief    Organic 

Constituents  op  the  Animal  Body -8 

Section  B.— Inorganic  Constituents »* 

CHAPTER  ni. 
Blood— Chyle— Lymph— Milk ^-^ 

CHAPTER  IV. 

Morbid  Conditions  of  Urine 103 

CHAPTER  V. 
Morbid  Conditions  of  the  Digestive  Secretions    .       .    173 


Morbid  Products 


CHAPTER  VI. 

235 


Clinical   Chemistry. 


CHAPTER  I. 

Section  A. — Organic  Constituents  of  the  Animal 
Body, 

1.  Object  of  study. —  It  is  proposetl,  in  the 
present  work,  to  confine  our  attention  to  those  points 
of  chemistry  in  so  far  as  they  relate  to  the  study  of  the 
chemical  phenomena  concerned  in  eflecting  abnormal 
qualitative  and  quantitative  changes  in  the  constitu- 
tion of  the  tissues  and  fluids  of  the  animal  body,  and 
their  practical  bearing  in  relation  to  clinical  medicine 
and  pathology.  Before,  however,  proceeding  to  the 
main  object  of  study  of  this  branch  of  science,  it  will 
be  necessary  to  consider  briefly  the  proximate  and 
ultimate  composition  of  the  principles  of  the  animal 
body^  and  the  nature  of  the  processes  which  produce 
the  various  decompositions  and  variations  that  are 
constantly  occurring  under  normal  conditions. 

2.  Clicniical  composition  of  the  tissues 
and  fluids. — If  we  submit  a  tissue  or  fluid  to  the 
action  of  heat,  we  find  that  with  a  moderate  degree, 
100°  C,  it  loses  weight  and  becomes  dry;  the  loss  of 
weight  is  due  to  removal  of  water  ;  the  dry  residue 
repi'esents  the  solid  material  present  in  the  substance 
submitted  to  analj'sis.  If  the  heat  be  now  raised  con- 
siderably, the  dry  residue  chars  or  carbonises,  showing 
the  presence  of  organic  matter  ;  if  the  heat  be  long  con- 
tinued this  undergoes  complete  combustion,  leaving  an 

B 


2  Clinical  Chemistry.  [Chap.  i. 

asli  which  resists  all  farther  change  on  the  application 
of  heat ;  this  ash,  which  consists  of  mineral  salts,  is 
known  as  the  inoeganic  residue.  If,  however,  we 
submit  the  tissue  or  fluid  to  a  slightly  more  complex 
analysis,  we  shall  find  that  the  organic  and  inorganic 
residue  consist  of  various  substances,  each  of  which 
can  be  removed  by  appropriate  means.  For  instance, 
if,  after  having  driven  off  the  water,  we  treat  the  dry 
residue  with  ether,  we  find  that  the  etherial  solution 
will  yield,  on  evaporation,  a  greasy  residue,  which 
represents  the  fats  extracted  from  the  tissue  or  fluid. 
If,  after  the  removal  of  the  fatty  matters,  we  treat 
the  original  residue  successively  with  boiling  alcohol 
and  boiling  water,  we  shall  find,  on  evaporating  the 
alcoholic  solution  and  the  aqueous  solution  respec- 
tively, that  each  will  give  a  residue  containing  sub- 
stances soluble  in  these  agents,  and  which  have  been 
extracted  from  the  original  mass  by  their  means. 
These  substances,  which  are  various,  are  designated  as 
EXTRACTIVES,  and  consist  chiefly  of  certain  organic 
substances  such  as  urea,  uric  acid,  ki-eatin,  etc.,  and 
the  SOLUBLE  salts  of  the  inorganic  constituents,  whilst 
to  separate  them  from  each  other  further  means  of 
analysis  have  to  be  employed,  and  special  tests  ap- 
plied to  identify  their  characteristic  reactions.  After 
the  fatty  matter  and  the  alcoholic  and  aqueous  extrac- 
tives have  been  removed,  there  remains  an  elastic  and 
somewhat  horny  mass,  which  consists  of  proteid 
material  (albumin,  fibrin,  globulin,  etc.),  and  which 
chars  on  being  burnt,  leaving  a  residue  of  such  salts  of 
the  inorganic  constituents  which  are  insoluble  in 
boiling  water,  and  some  of  the  soluble  salts  not  taken 
up  by  extraction  by  water.  By  this  elementary 
analysis  we  have  learnt,  first,  that  the  tissue  or  fluid 
consists  of  water  and  solids ;  secondly,  that  the  solids 
consist  of  organic  and  inorganic  substances,  and  that 
these  may  be  further  divided  :  (1)  The  organic  into 


Chap.  I.]  Orgaxic  Constituents.  3 

proteid  substances,  fatty  matters,  and  extractives  ;  (2) 
the  inorganic  into  soluble  and  insoluble  saline  con- 
stituents. The  next  step  in  the  investigation  is  (1)  to 
separate  and  distinguish  the  constituents  present  in 
each  group  from  each  other  ;  in  the  Protcids,  the 
various  albumins ;  in  the  Fats,  the  saponifiable  fats, 
cholesterin,  etc. ;  and  in  the  Extractives,  the  urea,  uric 
acid,  etc.,  and  the  composition  of  the  Soluble  and  In- 
soluble salts ;  (2)  to  determine  the  nature,  special 
characteristics,  and  ultimate  chemical  composition  of 
each  substance  so  sejiarated. 

3.  Composition  and  constitution  of  or- 
ganic substances. — There  is  no  essential  difference 
between  organic  and  inorganic  chemistry.  Organic 
chemistry  is  simply  the  chemistry  of  carbon  compounds, 
and  accordingly  we  find  that  the  organic  principles  we 
meet  with  in  the  animal  body  consist  of  carbon  united 
in  various  proportions  with  hydrogen,  oxygen,  nitro- 
gen, and  some  loss  abundant  elements,  such  as  sulphur, 
phosphorus,  and  iron. 

4.  IVitrog:cnous  and  iion  -  nitrog^enous 
compounds. —  The  carbon  comjiounds,  or  organic 
princiiDles,  for  purpose  of  convenience  ai'e  divided  into 
two  distinct  groups,  viz.  :  (1)  The  non-nitrogen- 
ous, and  (2)  the  nitrogenous ;  those  in  which  the 
element  nitrogen  is  absent,  and  those  in  which  it  is 
present.  Both  these  groups  are  represented  by  the 
principles  which  form  the  basis  of  the  animal  tissues 
and  fluids,  the  first  by  the  starchy,  saccharine,  and 
oleaginous  principles,  the  second  by  the  proteid  or 
albuminous.  These  principles,  which  are  usually  dis- 
tinguished by  the  term  proximate,  after  fulfilling  their 
purpose  in  the  economy,  undergo  a  series  of  changes 
{nietaholic),  are  broken  up  and  oxydised,  and  are 
finally  reduced  ;  the  former  to  carbonic  acid  and  water, 
the  latter  to  carbonic  acid,  water,  and  ammonium  cai'- 
bonate   (urea).      But   before    this   final    reduction    is 


4  Clinical   Chemistry.  [Chap.  i. 

reached,  various  intermediate  products  are  produced ; 
thus,  the  oxydation  of  the  non-nitrogenous  principles 
yields  lactic  acid  OjIIgOs,  oxalic  acid  O2H.O4,  acetic 
acid  CgH^O^,  formic  acid  CH2O2,  and  ultimately 
carbonic  acid  CHgO,.  The  nitrogenous  group,  in  ad- 
dition to  the  formation  of  products  identical  with  the 
above,  yield  by  oxydation  a  series  of  bodies,  the  lowest 
term  of  which  is  urea,  the  ammoniated  form  of  car- 
bonic acid ;  thus,  leucin  CgHigNOg,  and  kreatin 
O4H9N3O2,  and  perhaps  uric  acid  O5H4N4O3,  are 
recognised  antecedents  of  urea  CH^NgO. 

5.  €las$)ilication  of  the  compounds  of 
carbon. — These  are  (1)  the  compounds  of  carbon 
with  hydrogen,  or  the  hydrocarbons ;  (2)  the  com- 
pounds of  carbon  with  nitrogen. 

(1)  The  hydrocarbons. — The  classification  of 
these  bodies  is  based  upon  the  atomicity  of  carbon, 
which,  being  a  tetrad  element,  requires  4  atoms  of 
hydrogen,  or  some  other  monad,  for  its  full  saturation, 
i.e.,  to  satisfy  all  its  combining  powers  ;  the  fully 
satisfied  hydrocarbon  molecule  will  therefore  be  repre- 
sented by  the  formula  OH4.  Each  additional  atom  of 
carbon  i-equires,  however,  only  two  additional  atoms 
of  hydrogen  to  maintain  the  saturation,  because  a 
portion  of  the  combining  power  of  each  carbon  atom 
is  employed  in  linking  the  carbon  atoms  together. 
The  following  diagram  illustrates  this  important 
theory,  which,  it  must  be  remembered,  is  applicable  to 
all  kinds  of  carbon  compounds. 

CH4.  CaHg.  CJgHg.  C4H10. 

CHHH      (SJiS^ 


CHHHH.     {  gg™    j  CHH 


CHH 


\  CHH 

CHHH  [qJJJJJJ 

It   follows  from   this  that  all   carbon  compounds 


Chap.  l.|  O/i'OAiY/C    C\k\STITUK.\TS.  5 

lurange  themselves  in  series,  tlie  members  of  which 
differ  from  one  another  by  CHa  or  by  some  multiple 
of  CH...  Thus  we  have  formic  acid  CHnOa,  acetic 
acid  C2H4O2,  propionic  acid  CgHi-Oo,  and  so  on. 
Series  of  this  kind  are  termed  homofogous  series,  and 
the  members  are  said  to  be  homoloc/ues  of  one  another. 

(a)  Hydrocarbon  radicals.  From  the  above  con- 
siderations, we  deduce,  as  the  general  formula  for  a 
saturated  hydrocarbon,  the  expression  C„H2„  +  2,  in 
which  n  may  denote  any  number  of  atoms.  If  a 
hydrocarbon  contains  a  less  number  of  hydrogen 
atoms  than  the  above  formula  requires,  it  is,  or  may 
be,  a  radical;  tliat  is,  it  may  exist  in  compounds, 
and  play  therein  the  part  of  an  elementary  atom, 
."^ome  hydrocarbons,  however,  which  appear  from  their 
formulae  to  be  unsaturated  are  really  saturated,  or  at 
any  rate  have  an  atomicity  less  than  that  indicated  by 
the  above  theory.  It  is  not  necessary  in  this  work  to 
enter  into  the  theoretical  explanation  of  this  apparent 
anomaly. 

The  atomicity  of  such  a  radical  must  obviously 
depend  on  the  number  of  hydrogen,  or  other  monad 
atoms  required  to  complete  it.  Thus  the  radical  CH,, 
is  a  monad,  CH^  a  diad,  and  CH  a  triad.  Their 
function  in  compounds  is  well  illustrated  by  their 
chlorides,  which  are  strictly  comparable  to  metallic 
chlorides. 

Chloride  of 
sodium  NaCl.       zinc  Zn"CL       bismuth  Bi"Cls 

methyl  CH3CI.       methylene  CHXl      formyl     CHCI3 

Those  of  the  hydrocarbon  radicals  which  contain 
an  even  number  of  hydrogen  atoms  are  cai)able  of 
existing  in  the  separate  state,  and  most,  but  not  all  of 
them,  have  actually  been  prepared.  Ethylene  CoH.„ 
and  acetylene  C-.H^i  f-i's  examples.  Those,  on  the 
other  hand,  which  contain  an  uneven  number,  such  as 


Clinical  Chemistry. 


LChap.  I. 


methyl  CHg,  ethyl  CgHg,   and  glyceryl  C3H5,  cannot 
exist  in  the  free  state,  but  only  in  compounds. 

The  names  and  formulae  of  a  few  of  the  more 
important  hydrocarbon  radicals  are  given  in  the 
following  table. 


Table   of  Principal   Htdrocarbon  Eadicals. 

Monads. 

DiADS. 

Triads. 

Methyl 

series. 

01e£ne  series. 

Glycerin  series. 

Methyl  . 

•    CH3 

+ 

+ 

Ethyl     . 

.    C2H5 

Ethylene    .  CaH^ 

Ethine  or  Acety- 
lene     .     .     .  C2H2 

Propyl  . 

.     CgHy 

Propylene  .  CgHo 

Propine  or  AUy- 
lene      .     .     .  C3II4 

Butyl     . 

•  C,H, 

Butylene    .  C^Hg 

Quartine  or  Cro- 
tonylene   .     .  CiHo 

Amyl     . 

•  C5H11 

Amylene    .  CgH-n, 

Quintine  or  Va- 
lerylene    .     .  C5II3 

Hexyl    . 

•         Cl8Hj(g 

Hexylene  .   CoH^a 

Sextine  or  Dial- 

lyl    .     .     .     .  CeH.o 

(b)  Hydrocarbons  of  the  aromatic  series. — Benzene 
CgHg,  and  toluene  Oj-Hg,  arc  the  most  important  mem- 
bers of  this  series.  By  the  rule  before  given,  they 
should  be  octads,  but  they  possess  the  properties 
of  saturated  hydrocarbons,  and  are  not  therefore  to 
be  reckoned  among  the  radicals.  From  them  are 
derived  the  important  monad  radicals,  phenyl  CgHg, 
and  toluyl  C7H7. 

The  hydrocarbons,  under  various  conditions  of 
oxygenation  and  dehydration,  form  various  well-known 
bodies,  as  alcohols,  aldehydes,  and  organic  acids. 

I.  Alcohol. — In  an  alcohol,  a  monad,  diad,  triad, 
etc.,  hydrocarbon  radical  replaces  one  or  more  atoms 
of  H  in  one  or  more  molecules  of  water.     It  is,  in 


Chap.  I.]  OrGAXIC    CONSTITUENTS.  7 

fact,    a    hydrate    of    a    hydrocarbon    radical,    as    the 
following  show  : 

(a)  Ordinary  ethyl  alcohol  C,H^O  is  formed  by 
the  monatomic  radical  ethyl  C,Hj  replacing  one  atom 

of  H  in  the  single  molecule  of  water  thus,    -,  r^  \  O. 

(6)  Glycerin,  or  glyceryl  alcohol  CaHsOj,  is  formed 
by   the    triatomic    radical    glyceryl    C3H5'"    replacing 

3  atoms  of  H  in  the  treble  molecule  of  water  -^  \  O3 
thus      3     3     I  r\ 

(c)  Mannite  CgHi^Og,  a  saturated  hexatomic  alco- 
hol, is  formed  by  the  hexatomic  radical  C^Hg  replacing 

H    I 
6  atoms  of   hydrogen  in  the   molecule  tt*^  >  Og  thus, 

II.  Aldehydes  (alcohol  de  h)jdro(/enatus). —  If  an 
alcohol  be  submitted  to  oxydation  ib  loses  two 
atoms  of  H,  and  is  converted  into  a  neuti-al  body, 
called  an  aldehyde,  which,  ha"VT.ng  a  great  affinity  for 
oxygen,  rapidly  absorbs  it  from  the  air,  and  is  con- 
verted into  an  acid.  Aldehydes  are  therefore  com- 
pounds intermediate  between  the  alcohols  and  the 
acids. 

(a)  Ethyl  alcohol  CoH^O  deprived  of  2  atoms  of 
H  forms  ethyl  aldehyde  QJ3.^0,  and  ethyl  aldehyde  by 
oxydation  yields  acetic  acid  CoH^O^. 

(6)  Mannite  C^Hi^O^  deprived  of  two  atoms  of  H 
forms  mannitose  C^Hi  O^,  a  sugar  isomeric  with 
glucose,  dextrose,  and  other  saccharine  bodies,  which 
are  called  carbo-hydrates.  These,  however,  are  not  all 
aldehydes  (some  are  ethers,  others  alcohols),  but  they 
are  all  derivatives  of  the  hexatomic  radicals.  And 
mannitose  by  oxydation  yields  mannitic  acid  C6H12O;. 
Ketones   or  acetones   ai'e   bodies    isomeric   with    the 


8  Clinical  Chemistry.  ■  [Chap.  i. 

aldehydes,  but  are  distinguished  from  them  with  regard 
to  their  behaviour  with  oxygen  and  hydrogen.  With 
the  former,  an  aldehyde  vinites  directly  to  produce  an 
acid  ;  with  a  ketone  or  acetone  two  acids  are  formed. 
With  the  latter,  an  aldehyde  forms  a  primary  alcohol, 
whilst  with  a  ketone  a  secondary  alcohol  is  produced. 

III.  Organic  acids. —  As  stated  above,  the  or- 
ganic acids  may  be  regarded  as  alcohols,  in  which  a 
portion  of  the  hydrogen  of  the  radicals  is  replaced  by 
oxygen.  They  are  therefore  formulated  as  derived 
from  a  single,  double,  or  treble  molecule  of  water  by 
the  replacement  of  H,  II3  or  H,  by  a  monad,  diad,  or 
triad  oxygenated  liydrocarbon  radical. 

Examples : 

(a)  Acetic  acid  C2H4O2  is  formed  by  the  oxydised 
radical  acetyl  C2H3O,  which  has  replaced  one  atom  of 

H  in  water,  thus     ^    \t\  ^• 

(h)  Gly collie  acid  CgH^Og  is  a  double  molecule  of 
water  in  which    half    the  hydrogen   is   replaced    by 

glycollyl    ^    Vr  f  Oj.      In  fact,  it  is   ethylene  alcohol 

P  FT  1 
"fT*  [  ^2  ii^  which  two  atoms  of  hydrogen  of  ethy» 

lene  are  replaced  by  one  atom  of  oxygen. 

(c)  Oxalic  acid  C2H2O4  is  a  double   molecule    of 

water   in    which   half    the  hydrogen  is   replaced    by 

CO) 
oxalyl      TT^  >  O2.      Here  the  whole  of  the  hydrogen  is 

replaced  by  oxygen.  It  will  be  seen  that  both  these 
acids  are  related  to  ethylene  alcohol  as  acetic  acid  is 
to  ethyl  alcohol. 

Amines. — When   a  hydrocarbon   radical   replaces 

the  tj'pical   hydrogen    of   the   molecule    H  [  N,    the 

H) 
resulting  compound  is  called  a  primary,  secondary,  or 


I  i.ap.  1.:  Okuaxjc  Co.ysTJTUEyjs.  9 

tortiary  amine,  accorcling  iis  one,  two,  or  three  atoms 
of  hydrogen  are  replactid.  Thus,  the  following 
amines  are  obtained  by  the  substitution  of  the 
hydrogen  of  ammonia  by  methyl. 

Ammonia. 

H  l-N. 
HJ 


Amides. — When  an  acid  radical  replaces  any  part 
of  the  typical  hydrogen  of  ammonia,  the  resulting 
compound  is  called  an  amide.  As  some  of  the 
amides  play  a  very  important  part  in  the  animal 
economy,  it  is  necessaiy  to  study  their  constitution  a 
little  more  closely. 

For  this  purpose  it  will  be  convenient  to  write 
the  formulae  of  a  few  important  acids  in  a  foi-m  "which 
is  a  slight  variation  of  that  previously  used. 


Methylamine. 
CH3I 

H     K 

HJ 

Dimethylamine. 
CH3] 

CH,  I  N. 
H 

Trimetbylamine. 
CH3] 

CH3fK 
CH3. 

Primary  amine. 

Secondary  amine. 

Tertiary  amine. 

C.HjO 

HO 

Acetic      acid 

^      aHpj, 

0:H0, 

HO 

-I- 

Benzoic        „ 

^    '""^o 

0„H,0 

HO 

+ 

HO 

Glycollic      ,. 

=      C.H^j0. 

C,0, 

HO 

HO 

4. 

Oxalic          ,, 

=       c,o, ) 

C..,H,0 

HO 

HO 

Lactic          „ 

Ho.l     ' 

C3O3 

HO 

HO 

INIesoxalic    „ 

-      c.O},^ 

lo  Clinical  Chemistry.  [Chap.  i. 

In  the  above  table  we  have  acids  of  three  different 
kinds,  all  capable  of  yielding  amides. 

(1)  In  acetic  and  benzoic  acids  we  have  examples 
of  acids  which  are  simply  monobasic.  The  amides  of 
these  acids  are  called  monamides,  and  are  very 
simple : 

Aeetamide,  Benzamide. 

C,H30  1  C,H,0  1 

H      J^  N.  H      [  N. 

H      J  H     j 

They  differ  from  the  corresponding  amines,  just  as 
the  acids  do  from  the  alcohols. 

(2)  Oxalic  and  mesoxalic  acids  are  examples  of 
dibasic  acids.  They  are,  in  fact,  dihydrates  of  the 
radicals  CgOg  and  C3O3.  Now  these  radicals,  being 
diads,  are  capable  of  replacing  two  atoms  of  hydrogen 
in  the  double  molecule  of  ammonia.  In  this  way 
neutral  amides  of  the  kind  called  diamides  are  formed. 

Urea  is  by  far  the  most  important  of  the 
diamides. 


Oxamide 

Urea 

(oxalyl  diamide) 

(carbonyl  diamide). 

CAl 

CO] 

hJn, 

hJ 

HJ 

But  from  all  dibasic  acids  a  monad  as  well  as  a 
diad  radical  may  be  derived  by  merely  deducting  HO. 
Thus  from  sulphuric  acid,  SO2  HO  HO,  we  get  not 
only  the  diad  radical  SOj,  but  also  the  monad  radical 
SO2  HO.     The  following  formulae  exhibit  this  : 

(SO2)"     HO     HO 
(SO2       HO)'  01 
(SO2)"    CI,. 


Chap.  I.]  Organic  Coxstituents.  ii 

When  one  of  these  monntojnic  radicals  of  a 
dibasic  acid  replaces  the  hydrogen  of  ammonia,  a 
monamide  is  formed.  But,  as  there  is  still  one  atom 
of  replaceable  hydrogen  attached  to  the  radical,  this 
atom  can  at  any  time  be  replaced  by  a  metal  or  a 
hydrocarbon  radical,  and  thus  the  acid  character  is 
not  entirely  lost.  From  a  dibasic,  the  acid  becomes, 
in  fact,  a  monobasic  one.  Acids  of  this  kind  are 
called  amic  acids.     Thus  we  have 

Oxomic  acid.  Silver  oxamate.  Methyl  oxamate. 

CO^  HO  ]  CoO.,  A,0 )  CO.,  CH3O  ] 

H  ^  N.  H  ^  N.  KVN. 

hJ  HJ  HJ 

(3)  Glycollic  and  lactic  acids  are  examples  of  acids 
which  are  diatomic  as  to  their  structure  and  monobasic 
as  to  their  properties.  Only  one  of  the  two  typical 
hydrogen  atoms  that  each  contains  can  be  replaced  by 
metals.  The  diflerence  has  been  indicated  in  the 
formulfB  given  above  for  the  acids  by  marking  the 
replaceable  hydrogen  by  a  plus,  and  the  non-replace- 
able by  a  minus,  sign.  The  eflect  of  this  peculiarity 
is  that  Uoo  monad  radicals,  one  neutral  and  one  acid, 
can  be  derived  from  each  acid.  These  radicals  replace 
one  atom  of  hydrogen  in  the  single  molecule  of 
ammonia,  just  as  the  monad  radicals  of  dibasic  acids 
do,  and  monamides  are  formed  ;  but  these  monamides 
are  amic  acids  if  the  radical  so  introduced  contain  the 
replaceable  atom  of  hydrogen,  or  neutral  amides  if  it 
contain  only  the  non-replaceable  atom.  Thus  from 
glycollic  acid  we  have 

Glycollamic  Potassivmi  Metliyl 

acid.  glycollamate.  glycoUamate. 

C2H2O  HO  ]      anp  Ko  \       aH,o  CH3O  ^ 

H  In     "        H  In        '       H  j-N 
hJ  hJ  HJ 


T2  Clinical   Chemistrw  [Chap.  i. 

Glycollamide. 

and  also  Q^f>  HO  ] 

H  f-N. 
HJ 

Analogous  to  this  last  we  Lave  leucin,  the  neutral 
amide  of  leucic  acid,  which  is  one  of  the  homologues 
of  glycollic  acid. 

Derivations  of  urea.  — A  somewhat  numerous 
and  complex  class  of  bodies  is  known,  the  members 
of  which  contain  radical,  or  residues  of  urea,  together 
with  radicals  derived  from  various  acids.  Many  of 
the  deiivatives  of  uric  acid  belong  to  this  class, 
as  also  do  the  important  compounds  kreatin  and 
Jcreatinin. 

In  many  cases  great  difference  of  opinion  exists 
as  to  the  exact  structure  of  these  compounds,  as  they 
may  be  desci'ibed  by  several  formulae.  Kreatin  is 
generally  considered  as  containing  residues  of  urea 
and  sarcosin  (methyl-glycocin).  Its  formula  on  the 
ammonia  type  may  therefore  be  written  as  follows  : 


CO 
C,H,0  H.,N 


h- 


h! 


It  is  capable  of  taking  up  the  elements  of  water 
and  splitting  into  urea  and  sarcosin.  The  following 
comparison  of  the  formulae  of  these  two  compounds 
will  serve  to  illustrate  this.  The  atoms  which  have 
to  be  removed  to  produce  kreatin  are  printed  in  italics. 

Sarcosin  C.H.O  NIT^  CH.,  0\ 

Urea        CO        NH^    K //J' 

Compounds   which   contain   one    urea  radical  ai^e 


Chap.  M 


Org  A  xic  Cons  tituents. 


cjilled  monureides.  Kreatin  is  a  monureicle,  and  so 
are  paraban  and  alloxan,  which  are  obtained  by  thu 
oxydation  of  uric  acid. 


Piu-aban. 

CO    ) 

c,o.  In,      = 


Radical  of  oxalic  acid. 

CoO.. 


Alloxnn. 

CO   ) 

C3O3 '  N,        = 
H,) 


Radical  mesoxalic  acid. 

CO, 


Radical  of  uron. 
COH3N,. 

Radical  of  urea. 

COH,N.. 


Compounds  which  contain  two  urea  radicals  are 
called  diureides.  Allantoin,  xanthin,  hypoxanthin, 
and  uric  acid  belong  to  this  class.  There  is  still  some 
doubt  as  to  the  exact  constitution  of  uric  acid.  It  is 
best  represented  by  the  hypothetical  formula  as  con 
sisting  of  one   radical  of  tartronic  acid  and   two  of 


TartroDic  acid.  Urea. 

C3HA    +    2C0H,N, 


Uric  acid.  "Water. 

C,H,N,03    +    4H„0. 


(2)  Compounds  of  carbon  with  nitrog^en* — 

Carbon  and  nitrogen  do  not  directly  unite,  but  there 
exists  a  series  of  compounds  containing  the  monatomic 
radical  CX.  called  cyanogen.  These  cyanogen  com- 
pounds may  be  regarded  as  derivations  of  ammonia, 
and  are  also  connected  with  the  compounds  formed 
by  oxalic  acid  with  ammonia.  Thus,  we  saw,  when 
considering  the  amides,  the  diad  radical  of  oxalic  acid 
was  capable  of  replacing  two  atoms  of  hydrogen  in 
the  double  molecule  of  ammonia,  forming  a  neutral 
amide  of  the  kind  called  diamide ;  thus,  urea  also 
belongs  to  this  group  of  diamides,  since  in  it  the  diad 


14  Clinical   Chemistry.  [Chap.  i. 

radical  CO"  replaces  two  atoms  of  hydrogen  in  a  double 
molecule  of  ammonia. 

Oxamide  (oxalyl  diamide). 


Urea,  however,  can  be  formed  directly  by  heating  am- 
monium cyanate ;  thus, 

Ammonium  cyanate. 

CN 


NH,  ^  ^ 


Other  compounds  of  carbon  with  nitrogen  exist,  whose 
exact  constitution  are  not  yet  precisely  determined, 
(a)  Alkaloids  :  nitrogenous  bases  believed  to  belong  to 
the  compound  ammonias ;  they  combine  with  acids 
to  form  salts,  and  double  crystallisable  salts  with 
platinic  chloride.  They  are  derived  from  the  vegetable 
kingdom,  therefore  their  presence  in  the  animal  tissues 
and  fluids  when  found  in  them  is  only  incidental.  A 
class  of  bodies  derived  apparently  from  putrefactive 
changes  of  animal  substances  called  jytoamines  are 
closely  related  to  these  vegetable  alkaloids,  and  may 
be  mistaken  for  them,  especially  for  strychnia. 
(/3)  Certain  Colouring  matters,  of  which  the  indigo 
group  is  the  chief.  Indol  CgHyN,  one  of  the  products 
of  pancreatic  digestion,  stands  at  the  head  of  this  series, 
of  which  uro-xanthin  or  indigogen,  one  of  the  urinary 
pigments,  and  indican,  a  glucoside  of  indigo,  are 
members.  (7)  A  Ibuminous  or  Proteid  substances,  such 
as  fibrin,  casein,  globulin,  egg  albumin,  etc.,  which 
form  the  basis  of  the  tissues  and  fluids  of  the  body. 
Some  chemists  hold  that  the  proteids  are  formed  by 


Chap.  I.]  Organic  Constituents.  15 

the  combination  of  an  .azotisetl  principle,  of  a  dibasic 
acid  character,  with  di(lerent  saline  bases  in  varying 
j)ropoi"tions.  Others,  that  these  substances  contain  a 
I'adical  called  protein,  combined  with  more  or  less 
hydrogen,  sulphur,  and  phosphorus,  according  to  the 
nature  of  the  substance. 

6.  Sjiillicsis  and  analysis. — For  many  years 
it  was  supposed  that  organic  substances  could  be 
formed  only  by  the  agency  of  a  living  organism.  In 
1828,  however,  Wohler  obtained  urea  by  evaporating 
ammonium  cyanate,  and  since  that  time  chemists 
have  obtained  by  artificial  means  a  large  number  of 
compounds  formerly  obtainable  only  from  animal 
or  vegetable  organisms.  These  syntheses  are  effected 
cither  by  bringing  together  molecules  of  simpler 
constitution  to  form  a  more  complex  body,  as  in  the 
case  of  hippuric  acid  ; 

Qlycocin.  Benzoic  acid.  Hippuric  acid. 

CjH„OH„NHO  +  C^HjO  HO  =  C^H^O  H(C7H50)N  HO  +  H^O. 

or  by  building  up  an  organic  compound  from  purely 
inorganic  sources  ;  as  Berthelot  obtained  formic  acid 
by  heating  carbon  monoxide  with  potassium  hydrate 
at  100°  C. 

Cai-bon  monoxide.         Potassium  hydrate.  Potassitun  formate. 

CO         +         HKO         =         ^-^-^  I O 

or,  as  Kolbe  formed  acetic  acid  from  carbon  di- 
sulphide. 

In  nature  this  formation  of  organic  compounds 
from  inorganic  materials  [synthesis)  is  effected  by  the 
agency  of  the  vegetable  kingdom.  The  plant  under 
the  influence  of  the  rays  of  the  sun  liberates  a 
quantity  of  oxygen  from  inorganic  constituents  such 
as   carbonic   acid,   water,   and   ammonium   carbonate, 


1 6  Clinical   Chemistry.  [Chap,  i, 

which  exist  in  the  soil  and  air,  converting  them  into 
those  saccharine,  oleaginous,  and  albuminous  prin- 
ciples which  form  its  tissues  and  juices,  and  which 
ultimately  furnish  the  animal  world  with  food.  For 
example,  carbonic  acid  by  deoxydation  under  certain 
conditions  may  yield  mannite  ;  thus 

6C0,   +   7H,0  —  13O  =  C^HiP^. 

That  plants  exert  this  deoxydising  power  is  readily 
shown  by  a  very  simple  experiment.  If  a  bunch 
of  fresh  green  leaves  be  plunged  into  a  broad  necked 
bottle  containing  fresh  spring-water,  or  water  contain- 
ing carbonic  acid  in  solution,  the  bottle  turned  mouth 
downwards  into  a  basin  of  water  so  as  to  exclude  the 
air,  and  the  whole  placed  in  strong  sunlight  for  an 
hour  or  more,  the  leaves  will  become  covered  with 
minute  bubbles  of  oxygen,  which  is  derived  from  the 
decomposition  of  the  carbonic  acid  of  the  water ; 
the  oxygen  being  set  free,  while  the  carbon  is 
absorbed  by  that  plant  to  form  its  tissues.  In  this 
process  of  deoxydation,  however,  a  considerable 
quantity  of  force  derived  from  the  sun's  rays  is 
rendered  latent,  or,  to  speak  more  accurately,  be- 
comes potential,  one  portion  being  taken  up  by  the 
liberated  oxygen,  the  other  accumulated  in  the 
tissues  and  juices  of  the  plant ;  and  this  force  will 
remain  latent  till  the  oxygen  and  carbon  are  again 
united. 

The  reunion  of  carbon  with  oxygen  is  effected, 
either  by  the  direct  burning  of  carbon  in  oxygen, 
as  takes  place  when  fuel  is  burnt  in  our  grates  or 
stoves ;  or  when  the  carbon  elements  of  food  and 
tissues  are  submitted  to  the  action  of  the  respired 
oxygen,  and  the  potential  energy  assumes  the  active 
or  hinetic  condition  of  heat  and  motion,  whilst  the 
carbon  compounds  are  reduced  again  to  their  original 


Chap.  I.J  OxyOATlON.  1 7 

inorganic  state  of  carbonic  acid,  water,  and  anunoniuni 
carbonate.  That  animals  exhale  carbonic  acid  is 
demonstrated  by  the  turbidity  proiluced  by  passing  a 
current  of  expired  air  through  lime  water,  the  lime 
being  converted  into  calcium  carbonate  or  chalk  ;  and 
we  know  that  oxygen  is  absorbed,  from  the  fact  of  its 
diminution  in  the  atmosphere  of  close,  crowded,  and 
ill-ventilated  apartments.  Thus  the  vegetable  organism 
is  chiefly  employed  in  building  up  sijntheticnllij  in- 
organic into  organic  matter,  whilst  the  animal  aiia- 
It/tica/Ii/  reduces  organic  compounds  back  again  to 
their  original  inorganic  constituents.  These  processes 
of  deoxytlation  anil  oxydation  do  not  at  once  raise  or 
retluce  the  various  substances  to  or  from  their 
elementary  condition.  On  the  contrary,  the  process  is 
slow  and  gradual,  several  intermediate  products  being 
formed.  De  Luca,  for  example,  has  shown  that  in 
the  ripening  of  the  olive  carbonic  acid  is  first  replaced 
by  certain  acids,  as  oxalic,  tartaric,  etc.,  and  these  by 
mannite  ;  which  in  its  turn  is  deoxydised  and  con- 
verted into  olein.  On  the  other  hand,  in  the  de- 
composition of  albumin  a  number  of  intermediary 
bases  and  fatty  acids  are  formed,  such  as  uric 
acid,  xanthin,  kreatin,  lactic  acid,  and  oxalic  acid, 
before  the  final  oxydation  to  urea  and  carbonic 
acid. 

7.  Oxydation  and  fornientatiou. — Although 
it  may  be  broadly  stated  that  the  processes  going  on  in 
the  animal  body  are  finally  analytic,  still  certain  syn- 
thetic processes  do  occur,  as  for  instance  the  conversion 
of  carbohydrates  into  fat,  and  the  elevation  of  the 
proteids  and  peptones  into  tissues  of  a  more  complex 
form.  These  processes,  however,  have  not  as  yet 
been  sufficiently  investigated.  The  downward  trans- 
formation towards  carbonic  acid  and  urea,  which 
non-nitrogenous  and  nitrogenous  substances  undergo, 
and  to  which  the  term  metabolism  has  been  applied, 
c 


1 8  Clinic  A  l  C hem  is  tr  \ '.  [Chap.  t  , 

have  been  the  subject  of  much  study  and  consider- 
ation, though  our  knowledge  is  still  very  imperfect 
in  this  direction.  Formerly  it  was  held  that  tissue 
changes  depended  on  the  amount  of  oxygen  taken 
in  by  the  lungs,  so  that  on  increased  respiration  a 
more  intense  combustion  took  place,  and  metabolism 
was  increased  with  the  production  of  more  carbonic 
acid  and  urea,  whilst,  when  respiration  was  impeded, 
oxydation  was  imperfectly  performed,  and,  as  a  con- 
sequence, many  of  the  intermediary  products,  as  oxalic 
acid,  uric  acid,  etc.,  were  not  burnt  off,  but  were 
eliminated  in  an  imperfectly  oxydised  condition.  It  is 
upon  this  view  that  most  of  the  chemico-pathological 
speculations  at  present  held  are  based.  But  the  view 
is  now  gaining  ground  tliat  the  cells  are  to  a  certain 
extent  independent  of  the  amount  of  oxygen  supplied 
to  them  by  respiration ;  that  is  to  say,  though  they 
originally  obtain  oxygen  by  the  process  of  respiration, 
they  are  able,  so  to  speak,  to  stow  it  away,  and  make 
use  of  it  independently,  under  certain  vital  conditions 
which  bring  about  intramolecular  changes  in  their  com- 
position, so  that  reduction  is  a  prior,  or  at  least  a 
simultaneous,  process  with  oxydation.  According  to 
this  view,  instead  of  increased  metabolism  being  the 
result  of  increased  oxydation,  it  is  the  increase  of  the 
intramolecular  action  in  the  cells  themselves  that 
occasions  the  demand  for  oxygen,  and  a  more  active 
condition  of  circulation  and  respiration.  Accordingly, 
in  fever,  the  earliest  step  is  the  increase  of  intra- 
molecular changes  in  the  cells  themselves,  under  the 
stimulus  probably  of  the  zymotic  poison ;  for  when 
the  stored-up  oxygen  is  exhausted,  then  a  demand  for 
a  fresh  supply  causes  an  increased  frequency  of  pulse 
and  respiration,  which  continues  so  long  as  the 
stimulus  (zymotic)  acts  on  the  cells  and  maintains 
this  abnormal  intramolecular  activity.  The  fact  that  an 
increase  in  the  amount  of  urea  excreted  by  the  urine 


Cl>ai).  I.]  FeRMENTATIOX.  IQ 

often  precedes  tlie  rise  of  temperature*  gives  support 
to  this  view,  as  does  the  fact  of  the  gradual  but  steady 
increase  of  pidse,  res])iration,  and  temperature,  during 
the  early  stages  of  febrile  action.  For  the  acceptance  of 
this  view  it  is  necessary  to  discard  the  idea  that  oxyda- 
tion  occurs  in  iho  blood  itself,  and  to  hold  that  though 
the  quantity  of  luenioglobin  in  the  blood  is  the  measure 
of  the  oxydising  power  within  the  body,  it  is  the 
tissues  that  determine  the  amoimt  of  oxydation.  It  is 
not  the  place  to  discuss  the  physiological  reasons  and 
experiments  on  which  the  view  that  the  oxygen  of 
artwial  blood  i)asses  into  the  tissues  is  based,  and  for 
whi-^h  the  reader  is  referred  to  Professor  Michael 
Foster's  work  on  "  Animal  Physiology ;"  it  will  be 
sufficient  to  state  that  it  is  founded  on  the  fact  that 
oxygen  in  the  arterial  blood  reaches  the  tissues -in  a 
state  of  high  tension,  while  the  oxygen  in  the  tissues 
is  in  a  state  of  low  tension.  As  a  consequence  oxy- 
haMuoglobin  becomes  i-educed  and  jiasses  on  as  venous 
blood. 

Among  the  processes  which  induce  transformations 
in  complex  organic  substances,  fermentation,  next  to 
oxydation,  holds  an  important  place. 

There  are  two  kinds  of  ferments  : 

(a)  The  organised  ferments,  such  as  the  yeast 
plant,  with  powers  of  growth  and  reproduction, 
and  whose  ferment  power  cannot  be  separated 
irom  the  ferment  organism  by  filtration  or  any 
solvent ; 

(6)  The  unorga7iisecl  or  the  soluble  ferments,  which 
are  freely  soluble  in  water,  and  are  incapable  of 
growth  and  reproduction.  These  are  the  salivary, 
gastric,  and  pancreatic  ferments. 

In  the  first  group  the  action  of  the  ferment  is 
towards  the  conversion  of  the  substance  into   carbons; 

*  Einger  ;  Med.-Chii-.  Trans.  ISJt).      Ralfe  ;  Mid.   Times  and 
Gazette,  Jan.,  187tJ. 


2  0  Clinical   Chemistry.  [Chap.  i. 

acid,    certain    intermediate    products    being    formed : 
tjius,  with 

(1)  Yeast  [Mycoderma  cerevisice) : 

Glucose.  Alcohol.         Carbonic  acid. 

CeK^Oe   +    2H,0   =   2aHgO   +    2CHA 

(2)  Lactic  acid  ferment  (Bacteriwrti  lacticutn): 

Lactose.  "Water.  Glucose.  Lactic  acid. 

Ci^H^-Pn  +  H,0  =  2C6H,20s  +  4C3H6O3 

(3)  Butyric  acid  ferment  (Baccillus  subtilis): 

\ddf  water.  ^ut^^  Carbon-      Hydroge.. 

2C3Ha03    +    2H2O    =    CJlfi,    +    2CH2O3    +    H4 

(4)  Ui'ea  ferynentation  (Micrococcus  urece): 

TTrPa  WHtPv  A.mmoniuin 

urea.  watez.  carbonate. 

CH4N2O  +  2H,0  =  (NH),C03 


In  the  second  group,  the  process  of  fermentation  is 
from  anhydrides  into  hydrates.  These  ferments  formed 
in  the  animal  body  have  been  called  enzymes,  and  their 
action  designated  as  enzymosis,  and  their  nature  as 
enzymic.     They  may  be  thus  enumerated  : 

(1)  Ptyalin  : 

starch.  Water.  Dextrin.  Glucose. 

(2)  Pepsin  pancreatin : 

Albumin  H-  n(H20)  =  Peptone  +  Leucin  +  Tyrosin  v 
Indol,  etc. 

(3)  Pancreatic  fat  ferment  : 

Suet.  Water.  Stearic  acid.         Glycerin. 

CsrH^oOe   +    3H,0    ^   sC.gHseO,    +    C3HA 


Cliap.  1.]  IXORCANIC    CONSTITUENTS.  2  I 

As  Ewald  has  aptly  observed,  and  as  we  sliall 
see  when  we  come  to  the  consideration  of  the  changes 
taking  phice  in  the  animal  fluids,  all  purely  physio- 
logical fermentations  in  the  animal  body  correspond 
to  the  unorganised,  all  pathological  to  the  organised 
ferments.  As,  for  instance,  the  undue  formation  of 
acetic  and  lactic  acids  in  the  stomach  and  intestinal 
canal,  and  the  decomposition  of  urea  in  the  bladder 
into  ammonium  carbonate  under  the  influence  of  the 
micrococcus  urere.  All  ferments  decompose  peroxide 
of  hydrogen  and  act  best  at  temperatures  between 
20° — 70"  C.  At  much  higher,  or  at  much  lower, 
temperatui'es,  the  action  is  destroyed.  For  the 
growth  of  organised  ferments  it  is  necessary  that 
they  should  be  supplied  with  sufficient  food,  of 
which  ammoniacal  salts  and  alkaline  phosphates  are 
the  chief. 


Sectiox  B. — Inorganic  Constituents  of  the 
Animal  Body. 

8.  Purposes  of  the  inorganic  constituents. 

— The  inorganic  constituents  subserve  two  important 
offices  in  the  economy,  viz.  : — 

(1)  Chemical.  —  In  effecting  certain  metamor- 
phoses in  tlie  tissues  and  fluids,  and  keeping  in 
solution  many  of  the  otherwise  insoluble  organic 
principles. 

(2)  Mechanical. — In  giving  strength  and  firmness 
to  those  textures,  which,  like  bone,  cartilage,  and 
muscle,  form  the  solid  portion  of  the  organism. 

It  must  not  be  overlooked,  however,  that  many 
inorganic  substances  are  incidentally  introduced  into 
the  body,  and  are  eliminated  without  subserving  ap- 
})arently  any  purpose. 


2  2  Clinical  Chemistry.  [Chap.  i. 

9.  The  cttemical  rdle  of  ttie  inorganic 
substances  in  tlie  org^anism. — The  fact  that, 
under  normal  conditions,  the  same  weight  of  saline 
constituents  are  recoverable  from  the  urine  and  faeces 
as  are  introduced  during  the  same  period  with  the  food 
and  drink,  led  physiologists  and  chemists  for  a  long 
time  to  imagine  that  no  change  took  place  in  their 
constitution  during  their  passage  through  the  body, 
and,  consequently,  to  overlook  the  part  played  by  the 
inorganic  substances  in  histogenesis  ;  or  their  influence 
in  producing  the  daily  and  hourly  variations  which 
occur  in  the  chemical  composition  of  normal  blood ; 
or  the  action,  physical  as  well  as  chemical,  the  in- 
organic constituents  of  each  tissue  have  on  the 
albumin,  fats,  water,  etc.,  that  compose  that  tissue, 
and  how  far  excess  or  diminution  of  these  con- 
stituents influences  oxydation  and  nutrition  going 
on  in  textures.  Professor  Parkes*  was  among  the 
first  to  draw  attention  to  the  vastness  and  com- 
plicity of  the  chemical  circulation  taking  place  in 
the  body,  and  the  necessity  for  studying  the  chemical 
relations  subsisting  between  the  blood  and  the  secre- 
tions. Attention  once  drawn  to  the  subject,  its  im- 
portance was  recognised  and  astonishment  expressed 
that  problems  which  so  manifestly  called  for  solution 
had  been  so  long  ignored.  Although  this  branch  of 
animal  chemistry  is  the  least  develojoed,  still  our 
knowledge  in  respect  to  it  is  advancing.  It  has  now 
been  shown  that  whilst  salts  pass  with  immense  and 
usually  uniform  rapidity  into  the  circulation,  and  from 
thence  to  tissues,  their  discharge  is  by  no  means  so 
regular,  and  they  are  detained  for  very  unequal  periods, 
which  apparently  depend  on  the  need  of  the  tissue  to 
which  they  are  supplied. 

By  feeding  animals  on  food  rich  with  acid  salts, 

*  Gulstonian  Lectures.     Med.  Times  and  Gazette,  vol.  i.,  p.  333, 
1855. 


Chap.  I]  FnORGANIC    CONSTITUENTS.  2T^ 

Hofrniiiiiii*  ami  Loscarf  liavc  .sliown,  tliat  liowcvor 
1,'ivat  the  toiKioiicy  of  uric  acid  and  of  the  acid  salts  of 
|>iiosplioric  acid  is  to  combine  with  Imscs,  yet  these 
were  not  witlidrawn  from  tin;  alkaline  blood,  but  were 
evidently  withheld  to  maintain  its  alkalinity.  Tlicse 
experimental  facts  are  borne  out  by  what  seems  to 
occur  in  scurvy.  That  disease  is  brought  about  by 
the  prolonged  withdrawal  of  the  organic  acids  of 
vegetables  and  of  recently  killed  meat,  and  their 
salts,  from  the  dietary  of  those  affected.  These 
organic  salts  by  oxydation  yield  alkaline  carbo- 
nates. Now  the  alkaline  carbonates  are  the  salts 
I'hiefly  concerned  in  maintaining  the  alkalescence  of 
the  blood,  and  it  lias  been  found  that  when  these  are 
cut  off"  by  the  withdrawal  of  vegetable  food,  the 
alkaline  pliosphat(>s  are  not  excreted  in  the  u.sual 
amount  in  the  urine,  but  are  apparently  retained  in 
the  bo.ly  to  maintain  the  normal  alkalescence  of  the 
blood,  which  has  suffered  by  the  withdrawal  of  the 
alkaline  carbonates.  Dr.  Gaskell,|  too,  has  shown 
fxperimontally  that  a  dilute  alkaline  solution  acts 
upon  the  muscular  tissue  of  the  heart  so  as  to  produce 
a  powerful  contraction,  whilst  a  dilute  acid  solution 
l)roduces  an  opposite  effect.  Variations  in  the  alka- 
linity of  the  blood,  therefore,  pi'obably  cause  dis- 
t  urbances  of  the  circulation  and  so  effect  a  secondary 
chemical  influence  on  nutrition  as  well  as  a  direct  one. 
Dr.  Kinger,§  from  experiments  on  the  action  of  the 
salts  of  potash  soda  and  ammonia  on  the  frog's  heart, 
has  sho\vn  that  they  have  a  very  varying  action, 
both  as  regards  their  power  of  influencing  the  fre- 
quency   of   contraction  and    the  value  of   each  beat. 

*  "  Ueber  der  Uebergang  von  freien  Saurer  durcli  das  alkalisclie 
r.lut  in  den  Ham  ; "  "  Z.  fiir  Biologic,"  vii. 

t  "  Zur  alkalescence  des  Blutes  ;  "  "  Arcliiv  fiir  riiysiologie," 
I'lliiger.    1874. 

X  "  Journal  of  Physiologj',"  vol.  iii.,  No.  1.    1880. 

§  Med.-Cliir.  Trans,,  vol.  Ixv.,  p.  191.    1882. 


24  Clinical  Chemistry.  [Chap.  i. 

Moreover,  it  has  been  shown  that  the  various  salts 
introduced  into  the  body  do  not  pass  through  un- 
altered ;  probably  all  undergo  some  change.  In  the 
case  of  sodium  chloride  only  four-fifths  of  that  taken 
into  the  system  passes  out  as  such,  the  remaining  fifth 
being  decomposed  into  acid  potassium  phosphate. 
When  chloride  of  calcium  is  taken  by  the  mouth, 
nearly  the  whole  of  the  lime  is  found  in  the  faeces  as 
a  carbonate,  whilst  the  whole  of  the  chlorine  is  re- 
coverable from  the  urine  as  chloride  of  potassium  or 
sodium.  Such  decompositions  help  us  to  explain  the 
seeming  paradox  that  from  the  alkaline  blood  acid  se- 
cretions are  formed.  Thus,  in  the  case  of  the  urine  I 
have  shown  experimentally*  that  its  acidity  was  the 
result  of  the  decomposition  between  sodium  or  potas- 
sium bicarbonate  and  neutral  sodium  phosphate,  two 
salts  which  exist  in  the  blood ;   thus. 

Bicarbonate.     Neutral  phosphate.        Carbonate.  Acid  phosphate. 

NaHgCOa    +    Na^HPO,  =  Na^HCOa    +    NaH^PO^. 

And  Maly,f  who  has  investigated  the  subject  of  the 
acidity  of  the  gastric  juice  with  great  care,  has  come  to 
the  conclusion  that  the  hydrochloric  acid  is  derived 
from  the  decomposition  of  neutral  sodium  phosphate 
with  calcium  chloride;  thus. 

Neutral  sodium       Calcium  Tricalcic  Sodium.    Hydrochloric 

phosphate.  chloride.  phosphate.        chloride.  acii. 

Na^HPO,  -I-   sCaOl^  =  CaaPO^   -f   4NaCl   f   2HCI, 

the  acid  in  both  instances  diifusing  out  toward  the 
free  surface  of  the  secreting  membrane,  the  other  salts 
remaining  in  the  blood  and  returning  to  the  circula- 
tion. 

*  Lancet,  p.  29,  July  4th,  1874. 

t  " Zeitschrift  fur  Physiolog.  Chimie,"p.  174.    1877. 


Chap.  I.]  Inorganic  Const/tuhnts.  25 

10.   I>i<ii>tril»iitioii  of  flic  iiiorijaiiic  coiiNfi- 
lii('iit«!>  ill   tlie  (litrc'i'ciit   liH<mio«   iiii<l   lliii<ls.— 

'J'lio  following  table  gives  the  percentage  of  inorganic 
rosidue  in  tlie  principal  tissues  and  lluids  of  the  body. 
It  nnist  be  rcunemljered,  however,  with  regard  to  the 
fluids,  that  the  amounts  are  only  approximate,  since 
they  vary  gi-eatly  during  the  period  of  the  twenty-four 
hours,  under  the  ditierent  physiological  conditions. 

Takle  I. — Percentage  of  Inougamc  Resiuce  in 


I'.namol S)6'41 

l>('ntiiie 71-30 

I'.one 66-70 

Muscle 1-82 

Nerve 174 

Trine  (24  hours)       .     .  1-32 

lUood  plasma.     .     .     .  0-82 

Dlood  corpuscles .     .     .  0-72 


Pus 0-84 

Chyle 0  83 

Lvniph 0-72 

Bile 0-78« 

Gastric  juice.     ...  024 

8aliva 0-18 

Pancreatic  juice      .     .  — 


The  diflerent  inorganic  constituents  are  distri- 
butetl  in  very  Aarying  proportions  among  the  tissues 
and  fluids  ;  thus,  in  muscle,  in  100  jiarts  of  the  ash  the 
])otassium  salts  are  to  the  sodium  salts  as  58  to  '2?>, 
whilst  in  blood  they  are  as  6  to  79.  Again,  the 
distribution  of  the  inorganic  salts  in  blood  is  found 
to  difi'er  in  the  ash  of  the  plasma  and  corpuscles 
i-elatively  ;  thus,  in  the  ash  of  1000  parts  of  corpuscles 
there  is  3-G79  parts  of  potassium  chloride  and  2-343  of 
j)otassium  phosphate,  whilst  in  the  serum  the  potas- 
sium chloride  only  amounts  to  -408  and  a  mere  trace 
of  potassium  phosphate.  On  the  other  hand,  the 
serum  is  pai'ticularly  rich  in  sodium  chloride  whilst 
the  corpuscles  yield  but  little.  Dr.  Ringer's  experi- 
ments, already  alluded  to,  seem  to  throw  some  light 
on  the  reason  for  this  marked  divergence.  The  effect 
of  the  potassium  salts  on  the  action  of  the  heart,  says 

*  The  bases  combined  with  glycocholic  and  taurocholic  acids 
not  reckoned. 


26  Clinical   Chemistry.  [Chap.  i. 

Dr.  Ringer,  was  to  increase  contractility  and  excita- 
bility to  a  far  greater  extent  than  is  the  case  with  the 
sodium  salts,  and  therefore  the  former  are  to  be 
regarded  as  the  most  "  poisonoiis  "  in  their  action,  and 
Dr.  Ringer  infers  that  "  the  action  in  one  tissue  being 
selected  and  all  other  conditions  being  kept  as  far  as 
possible  identical,  if  one  salt  prove  itself  more  active 
than  another,  it  is  at  least  not  improbable  that  this 
same  salt  will  also  prove  itself  more  active  under  the 
more  complex  conditions  presented  by  the  organism  as 
a  whola"  It  can  therefore  be  conceived  that  it  is 
advantageous  that  the  sodium  salts  which  are  the  least 
active,  as  far  as  conditions  of  contractility  and  excita- 
bility  are  concerned,  are  those  which  remain  free  in 
the  serum,  whilst  the  most  active,  the  potassium 
salts,  are  fixed,  so  to  speak,  in  the  corpuscles  till 
required  to  play  their  part  in  the  nutrition  of  the 
tissues. 

11.  The  conditions  in  wliich  the  inor- 
g'anic  constituents  exist  in  the  tissues  and 
fluids. — The  inorganic  constituents  enter  and  pass 
out  of  the  system  as  crystalloids,  but  whilst  in  contact 
■with  organic  matter  they  seem  to  lose  their  crystalline 
form  and  become  colloidal,  and  thus  give  the  tissues 
and  fluids  their  homogeneous  appearance.  The  in- 
fluence of  colloid  media  upon  crystalline  form  has 
recently  received  considerable  attention,  and  a  further 
study  will,  no  doubt,  throw  considerable  light  on  the 
pathological  changes  occurring  in  the  solid  tissues, 
owing  to  morbid  conditions  of  the  colloidal  medium 
itself,  or  to  an  inadequate  supply  of  the  inorganic 
constituents  themselves,  or  to  irregular  distribution 
(excess  or  deficiency)  of  the  acids  and  bases.  Atten- 
tion was  first  drawn  to  the  subject  of  molecular 
coalescence  by  Professor  Rainej',*  and  his  work  has 

*  "  On  the  Mode  of  Formation  of  Shells,  of  Bone,  and  several 
other  Structures,  by  a  Process  of  Molecular  Coalescence."    18.58. 


Cliap.  I.J  /a'OKCAX/C    CoXS/l/UJiNiS.  27 

lii-en  ably  followed  up  by  Dr.  W.  M.  Ord,*  Dr. 
A'aiulykc  Cart(n-,f  and  Professor  llarting.;}:  The 
lullowing  ore  .some  of  the  most  important  conclu.sion.s 
arrived  at.  When  two  saline  solutions,  a.s,  for  in- 
stance, sodium  carbonate  and  calcium  chloride,  which, 
by  double  decomposition,  are  calculated  to  produce  an 
insoluble  carbonate  of  lime,  are  allowed  gradually  and 
.slowly  to  intermix,  through  the  intervention  of  a 
vi.scous  medium  (such  as  dissolved  gum  or  albumin), 
there  are  formed  by  the  union  of  nascent  salt  with 
colloid,  not  crystals  of  the  cari)onate,  but  small,  firm, 
rounded  bodies,  which  are  possessed  of  a  concentric 
and  radiate  structure,  and  to  whicli  the  term  sub- 
iiiurj>houii  is  apj)lied.  These  bodies,  though  dis^iosed 
to  adhere  to  any  surface,  connnonly  remain  free,  Vjut 
also  exhibit  a  tendency  to  meet  and  blend  together,  so 
as  to  lead  to  the  construction  of  a  laminar  series.  Tlie 
chief  conditions  that  influence  the  phenomena  of 
molecular  coalescence  may  be  thus  enumerated  :  (1) 
Nature  of  colloidal  medium ;  (2)  nature  of  earthy 
salts ;  (3)  temperature  of  the  solution  ;  (4)  density 
of  the  solution ;  (5)  rapidity  with  which  the  saline 
constituents  intermingle.  The  converse  of  "  molecu- 
lar coalescence  "  is  "  molecular  disintegration,"  wliich 
Dr.  Ord  pronounces  as  the  most  strikingly  original  of 
I'rofessor  liainey's  researches,  and  which  promises  to 
bear  much  fruit  in  the  elucidation  of  the  nature  of 
certain  bone  diseases  and  the  disintegi'ation  of  renal 
calculi.  The  inorganic  substances  occurring  in  the 
animal  tissues  and  fluids  are  not,  for  the  most  part, 
united  in  a  true  chemical  combination,  but  form,  so 
to  speak,  a  loose  physico-chemical  combination,  and 
are,    as   it     were,     held     in    solution,     from     which 

*  "  On  the  Influence  of  Colloids  upon  Crj'stalline  Form  and 
Cohesion."     1879. 

t  "  IMode  of  Formation  of  Urinary  Calculi."     1873. 

+  "  Artificial  Production  of  some  of  the  Principal  Organic 
Calcareous  Formations. "'     Utreclit.     1872. 


28  Clinical  Chemistry.  [Chap.  ii. 

they  can  be  removed  by  mechanical  means.  Thus, 
for  example,  if  some  tissue,  as  muscle,  be  minced 
very  fine  and  placed  in  a  dialyser,  and  the  dia- 
lyser  floated  in  water,  after  the  lapse  of  some 
hours  the  flesh  will  lose  its  consistence  and  become 
pulpy  and  jelly-like,  at  the  same  time  the  water 
will  increase  in  density  from  the  diffusion  of  the 
inorganic  salts  iiito  it ;  and  these  salts  can  be  obtained 
for  analysis  by  evaporating  the  diffusate.  This  pro- 
cess of  diffusion  is  the  best  method  for  ascertaining 
the  nature  and  chemical  composition  of  salts  as  they 
exist  in  the  tissues  and  fluids,  since  the  result  obtained 
by  incineration  is  an  artificial  one,  and  does  not 
represent  the  composition  of  the  inorganic  constituents 
as  they  exist  in  a  natural  condition  in  the  tissues ; 
since  in  burning  off  the  organic  matter  the  phos- 
phorus and  sulphur,  which  exist  in  proteid  substances, 
become  oxydised  and  form  phosphates  and  sulphates. 
By  applying  the  process  of  dialysis  as  a  means  of 
investigation  to  the  exact  constitution  of  inorganic 
constituents  as  they  exist  in  the  tissues,  R.  Maly  * 
has  arrived  at  very  important  results,  one  of  the  chief 
being  the  exact  nature  and  composition  of  the  saline 
constituents  of  the  blood. 


CHAPTER  II. 

Section  A. — Enumeration  op  the  Chief  Organic 
Constituents  of  the  Animal  Body. 

division  i. saccharine  and  starchy  principles. 

All  contain  six  atoms  (or  multiples  of  six)  of  carbon, 
are  generally  known  as  carbohydrates.     Bertholet  has 
shoAvn  that  these  substances  are  alcohols,  or  are  related 
*  Op.  cit. 


Chap.  II. J  S.lCCHAKIA'l-:    PRlNC/rLf-iS.  29 

to  tlic  alcohols,  of  tlic  liii^hor  polyatomic  radicals  (§  5). 
They  clo.sely  resoinblo  one  another  in  their  chemical 
characters  and  are  Isomeric,  are  neutral  in  their 
reaction,  and  have  little  disposition  to  enter  into 
combination.  They  have  all  a  strong  action  on 
polarised  light.     They  are  divisible  into  three  groups. 

Group  I.  Glucoses   n(CBHi208). 

12.  Oliicosc  C,iH|._,0,i  (syn.  cbxtrose,  grape  sugar). 
— In  jiure  state  crystallises  in  rhombic  tablets,  but  ig 
usually  met  with  in  irregular  warty  masses.  Soluble 
in  own  weight  of  cold  water,  the  solution  gives  a 
dextro-rotatory  power  +  57-6°.  Undergoes  vinous 
fermentation  when  yeast  is  added.  Albu7iiinons 
ferments  induce  lactic  and  subsequently  butyric  acid 
fermentation.  Solutions  of  grape  sugar  become  brown 
when  boiled  with  liquor  potassse,  and  picric  acid 
added  to  such  solution  gives  a  deep  mahogany  red. 
Alkaline  solutions  when  heated  reduce  cupric  salts, 
throwing  down  retl  precij^itate  of  oxide  of  copper.  An 
alkaline  solution,  heated  with  a  few  granules  of 
bi.smuth,  reduces  the  latter,  and  turns  it  black.  A 
solution  made  faintly  alkaline  with  sodic  carbonate, 
and  renderetl  blue  l)y  the  addition  of  indigo,  when 
heated  to  boiling,  without  agitation,  becomes  first  violet, 
then  yellow  ;  on  agitation  the  blue  colour  is  restored. 

LfSevulose  C^H|oO,j  (syn.  invert  sugar).  — 
Incapable  of  crystallisation.  Exists  as  a  syrupy 
residue.  Does  not  ferment  so  readily  as  grape  sugar, 
but  reduces  copper  from  alkaline  solutions  readily. 
DiO'ers  from  gi-ape  sugar  in  its  left-handed  polarisation, 
which  diminishes  as  temperature  rises;  being-  lOG^at 
15°  C.,-7y-o°  at  52°  C,  and -53°  at  90°  0. 

Inositc  CgHjoOg  +  2H._,0  (syn.  muscle  sttgar). — 
Crystallises  in  two  forms:  (1)  Large  rhombic  tables  ; 
(2)  small  tufted  groups  of  oblique  ])risms.  Soluble 
in  six  parts  of  water  at  20*^  C,  insoluble  in  alcohol 


30  .       Clinical  Chemistry.  [Chap.  ir. 

and  ether,  unfermentable  with  yeast,  no  action  on 
polarised  light ;  alkaline  solutions  do  not  reduce  salts 
of  copper,  but  give  a  greenish  tint  which  clears  up  on 
standing,  leaving  original  blue  solution,  but  which 
again  becomes  green  on  heating.  Heated  to  dryness 
on  platinuna  foil,  with  a  drop  of  nitric  acid,  the 
residue  moistened  with  ammonia  and  calcium  chloride 
yields  a  beautiful  rose  colour. 

Group  II.   Saccharoses  n(Ci2H220ii). 

13.  Saccharose  CjsHgaOn  (syn.  cane  sugar). — 
Crystals,  monoclinic  prisms,  very  soluble  in  water, 
insoluble  in  absolute  alcohol  and  water.  Solutions 
have  a  dextro-rotatory  power  +  73 -S*^,  Boiled  with 
water  for  some  hours  it  is  converted  into  a  mixture  of 
glucose  and  la^vulose,  or  ^'■invert  sugai:"  It  ferments 
with  yeast,  but  is  transformed  first  into  glucose.  Does 
not  at  fii'st  reduce  cupric  salts  from  alkaline  solutions, 
but  does  so  after  a  while.  In  the  intestines  cane 
sugar  is  converted  into  "  invert  "  sugar. 

Lactose  Qy^.^^O^^-\-H^O  (syn.  milk  sugar). — 
Crystals  rhombic,  soluble  in  six  parts  of  cold  water ; 
dextro-rotatory  power  =  +  59'3°.  Does  not  readily 
undergo  vinous  fermentation ;  reduces  copper  in 
alkaline  solutions.  Boiled  for  some  hours  with  dilute 
acids,  forms  galactose,  this  treated  with  nitric  acid 
yields  mucic  acid. 

Group  III.  Amyloses  n(CeHio05). 

14.  Amylum  CgHioOg  (syn.  starch). — Granules, 
rounded,  irregular  form,  marked  with  concentric 
laminse,  having  a  hilum  or  pore  on  surface.  Insoluble 
in  cold  water,  but  when  boiled  swell  up,  burst,  and 
form  paste   or  mucilage.       Solution  is  dextro-gyrous 

-f-  2 1 6°.  With  iodine,  starch  solutions  give  a  deep  blue 
colour,  which  it  loses  when  heated  to  100°  C,  but 
I'egains  it  on  cooling.     Diastase,  dilute  sulphuric  acid. 


Chap.  II.]  /■ATT)-    PrISXIPLTS.  3  I 

the  salivary  and  pancreatic  ferments,  convert  starch 
into  glucose  and  dextrin.  The  further  action  of 
saliva  is  probably  to  convert  the  dextrin  into  glucose 
by  the  assumption  of  water,  thus  : 

starch.  Water.  Glucose.  Dpxtrin. 

sCeH.oO^  +  H,0  =  C«H,A  +   2aH„0, 
and 

Dextrin.  Water.  Glucose. 

2CeH,o05   +     2ILO    =    2C«H,A- 

Dextrin  C^HioOs  (syn.  British  <fum). — A  yel- 
lowish powder,  soluble  in  water,  forming  a  viscous 
lluid.  Solutions  dextro-gyi'ous  —  -f  138'8°.  Witli 
iodine  gives  reddish  colour,  which  disappears  on 
heating  and  does  not  reappear.  Does  not  undergo 
vinous  fermentation,  or  reduce  copper  salts  till  con- 
verted into  glucose. 

Olycogeu  C^HioOg  (syn.  animal  starch). — Yel- 
lowish-white amorphous  substance.  Soluble  in  cold 
water,  insoluble  in  alcohol.  Readily  converted  into 
glucose.  "With  iodine  gives  a  similar  coloration  as 
dextrin,  but  is  distinguished  from  it  by  the  colour 
reappearing  after  it  had  been  lost  by  heating. 

DIVISION    II. THE    FATTY    PRINCIPLES. 

The  natural  oils  and  fata  existing  in  the  body  are 
all  compounds  of  glycerin  with  fatty  acids  ;  the  chief  of 
which  are  mixtures  of  stearic,  palmitic,  and  oleic  acids. 
Thus,  the  tri-stearin  of  suet  consists  of  three  parts 
of  the  radical,  stearyl  CigHsjO,  which  has  replaced  three 
atoms  of  typical  hydrogen  from  glycerin  C3H5  (0H)3 

thus,     /p  tt'o\  f  ^3-     They    are    neutral    bodies,    of 

soft  greasy  consistence,  highly  inflammable.  Insoluble 
in  water.     Soluble  in  ether,  benzol,  fluid  oils,  carbon 


32  Clinical  Chemistry.  [Chap.  ii. 

bisulphide,  chloroform,  and  hot  alcohol.  Heated  with 
alkalies,  they  are  saponified;  that  is,  the  fatty  acid 
unites  with  the  alkali  to  form  a  soap,  whilst  the 
glycerin  is  set  free.  Oils  and  melted  fats,  shaken  iip 
with  water  containing  albumin,  bile,  pancreatin,  etc., 
become  emulsionised ;  that  is,  the  fatty  matter  is 
broken  up  into  small  globules,  which  become  more  or 
less  permanently  suspended  in  the  aqueous  solution. 

15.  Stearin  CsyH^oOg  (syn.  tri-stearin). —  The 
chief  constituent  of  solid  fat.  Occurs  in  white  crystal- 
line nodules.  Melting  point  variable ;  65°  0.  to 
69"7°  C.  (Heintz).  Soluble  in  boiling  alcohol,  from 
which  large  square  scales  of  stearin  are  deposited  on 
cooling. 

16.  Palmitin  CsiHggOg  (syn.  tri-palmitin). — 
Fine  needle-shaped  crystals.  Melting  point  variable  ; 
mean  62-8''  0.  (Heintz).  The  substance  known  as 
margarin  consists  of  ten  per  cent,  of  stearin  and 
ninety  per  cent,  of  palmitin.  Margarin  is  obtained 
by  heating  fat  in  a  water-bath,  stirring  with  an  equal 
quantity  of  alcohol.  The  alcoholic  solution  on  cooling 
deposits  needle-shaped  crystals,  arranged  in  whorled 
groups  or  feathers.  The  melting-point  of  margarin  is 
lower  than  the  melting-point  of  its  two  constituents, 
being  47-8°  0.  (Heintz). 

17.  Olein  G^jfl-^Qfie  (syn.  tri-olein). —  Colourless 
oil,  remaining  liquid  at  0°  0. ;  exposed  to  air,  it  absorbs 
oxygen,  and  becomes  rancid.  Heated  to  280°  C,  it  is 
decomposed,  and  yields  sebacic  acid. 

18.  Olycerin  C3H5(OH)3. —  Colourless  syrupy 
liquid.  Soluble  in  water  and  in  alcohol.  Heated 
with  fatty  acids,  it  combines  with  them,  forming  ethers 
(glycerides)  which  constitute  the  neutral  fats. 

19.  Olycerin  -  phosphoric  acid  CsHgPOg. — 
Syrupy  liquid,  both  sour  and  sweet  to  taste.  It  is 
dibasic,  and  its  barium  and  calcium  salts  are  soluble 
in  cold  water,  but  not  in  alcohol.     Its  chief  interest 


Chap.  II.]  l'hor[-,iD  Principles.  33 

is  its  association  with  a  group  of  phosphorised  bodies, 
of  which  lecitliiu  is  the  chief. 


DIVISION    III.  —  rROTKID    PRINCIPLES. 

Those  constitute  tlie  basis  of  all  the  tissues  of  the 
Itody.  They  are  amorphous,  have  low  diil'usive  powers, 
turn  the  plane  of  polarisation  to  the  left.  Heated 
with  caustic  alkalies,  they  give  ofl'  auinionia,  volatile 
fatty  acids  as  formic,  acetic,  etc.,  and  yield  leucin, 
tyrosin,  and  glycocin.  Heated  with  strong  nitric  acid, 
tliey  give  a  yellow  colour,  which  turns  orange  on  tlie 
addition  of  ammonia  {xantJio-proteic  reaction).  Boiled 
with  mercuiic  nitrate  solution,  a  red  colour  i.^  deve- 
loped (Mil/un's  reaction).  With  acetic  acid  and  ferro- 
cyanide  of  potas.sium,  proteids  are  precipitated  from 
their  solutions.  Also  by  picric  acid,  tannic  acid,  or 
mercuric  chloride.  Acted  upon  by  the  gastric  and 
pancreatic  ferments  they  all  become  soluble,  and 
acquire  greater  diffusive  power. 

Group  I.  Native  albuinins. — Soluble  in  pure 
water. 

20.  Soriiin  albiiiiiiii.  —  Viscid  glairy  fluid. 
Neutral  in  reaction,  freely  soluble  in  pure  water.  Its  so- 
lutions have  a  spcciiic  rotatory  power  of  -  56°  C.  When 
heated  the  solutions  become  ojiaque  at  62'65°  C,  and 
coagulation  occurs  at  73'  C.  Strong  mineral  acids  also 
produce  coagulation,  but  they  are  not  precipitated  by 
sodium  chloride,  organic  acids,  nor  dilute  mineral  acids. 

£gg  albumin  diflers  fi'om  the  above  in  that  it  is 
coagulated  by  ether,  whilst  serum  albumin  is  not,  and 
that  the  specific  rotatory  power  for  light  is  -  35 'S"  C, 
instead  of  —  50"  C. 

Group  II.  Globulins.  —  Not  soluble  in  pure 
water,  but  in  dilute  neutral  saline  solutions. 

21.  Olobuliii  (syn.  crystallin). —  As  deposited 
iu  its  coagulated  form,  by  passing  a  current  of  carbonic 

D 


34  Clinical  Chemistry.  [Chap.  ii. 

acid  througli  its  aqueous  solution,  globulin  is  insoluble 
in  pure  water,  but  undergoes  solution  if  the  water  is 
saturated  with  oxygen.  It  is  also  soluble  in  dilute 
neutral  saline  solutions.  Solutions  of  globulin  become 
opalescent  when  heated  to  73°  C,  and  globulin  is 
deposited  at  93°  C.  Globulin  is  precipitated  from  its 
solutions  by  carbonic  acid  gas  and  by  alcohol.  (Con- 
stitxient  of  aqueous  and  vitreous  humours  of  eye.) 

Paraglohulin  (syn.  serum  globulin,  Jlbrinoplastic). 
— As  precij)itated  from  blood  serum  by  complete 
saturation  with  magnesium  sulphate,  paraglobulin 
is  soluble  in  water  saturated  with  oxygen,  in  dilute 
neutral  saline  solutions  (very  dilute  solution  of 
common  salt,  0'5  per  cent.,  precipitates  paraglobulin 
from  solution;  on  addition  of  more  salt  the  precipitate 
redissolves,  till  about  20  per  cent,  is  added,  when 
precipitate  recurs),  and  in  weak  solutions  of  alkaline 
carbonate,  from  which  it  is  precipitated  by  alcohol. 
Solutions  coagulate  at  75°  C,  but  vary  considerably, 
according  to  amount  of  saline  substance  present  in 
solution.  (Constituent  of  blood  serum,  and  plasma, 
colourless  corpuscles  of  lymph  and  chyle.) 

Fibrinogen. — As  obtained  from  blood  by  mixing 
one-third  its  volume  with  saturated  solution  of  mag- 
nesium sulphate,  filtering  and  precipitating  filtrate 
with  saturated  solution  of  common  salt ;  removing  the 
flaky  precipitate,  and  frequently  redissolving  and  re- 
precipitating  by  alternately  using  solutions  of  common 
salt  of  7  per  cent,  and  20  per  cent.,  to  render  it  quite 
free  from  paraglobulin.  After  the  last  precipitation, 
dissolve  in  cold  water,  in  which,  owing  to  the  salt 
adhering  to  the  precipitate,  it  is  soluble.  This  solu-. 
tion  coagulates  at  from  52°  0.  to  56°  C.  ;  when  serum 
or  a  solution  containing  fibrin  ferment  is  added,  fibrin 
is  formed.  (Constituents  of  blood  serum,  serous  fluids, 
and  many  pathological  transudations.)  The  fibrin 
ferment  is  prepared  by  adding  to  blood  serum  twenty 


Chap.  II.]  Pi^OTEiD  Principles.  35 

times  its  voIuiih^  of  alcoliol,  and  allowing  to  digest 
for  a  month  or  more.  Tlie  insoluble  matter  is  removed 
and  agitated  with  water  and  tlie  mixture  filtered. 
The  precipitate  is  then  dried  over  snli)huric  acid  and 
iinely  pulverised.  The  aqueous  solution,  added  to  a 
solution  containing  fil)rino[»lastic  and  fibrinogen,  causes 
immediate  coagulation. 

Hannorilohin. — Crystals  of  oxy-htemoglobin  are 
rhombic  plates  or  prisms  with  dihedral  summits  freely 
soluble  in  water,  insoluble  in  alcohol,  ether,  or  chloro- 
form. Solutions  of  oxy-ha-moglobin  rendered  suffi- 
ciently dilute,  give  two  absorption  bands  in  the  spec- 
trum in  the  yellow  and  beginning  of  green  between  D 
and  E,  the  band  nearest  D  being  tlie  smaller  and  darker. 
If  to  this  solution  we  add  annnoniacal  stannous  cldo- 
ride,  to  which  enough  tartaric  acid  has  been  added  to  pre- 
vent precipitation,  the  two  bands  fade  away,  and  there 
appears  a  single  broad  band  situated  almost  between 
the  two  preceding  ones.  This  is  the  band  of  reduced 
hajmoglobin.  Solutions  of  haemoglobin  readily  decom- 
pose at  temperatures  above  0°  C.  ;  on  the  addition  of 
acids  and  caustic  alkalies,  they  break  up  into  hcematin 
and  globulin  ;  treated  with  glacial  acetic  acid  and  any 
metallic  chloride,  it  is  decomposed  into  hcemin.  Other 
products  of  its  decomposition  ai'e  hcematoidin,  hcemo- 
chromogen,  Jicematopopphyrin. 

22.  Myosin. — As  prepared  by  washing  finely- 
minced  muscle  with  cold  water  till  a  precipitate  is  no 
longer  thrown  down  on  the  addition  of  mercuric  chlo- 
ride. The  residue  on  filter  is  then  treated  with  10  per 
cent,  solution  of  sodium  chloride,  strained  through 
linen,  the  resulting  liquid  filtered  and  precipitated  by 
the  addition  of  distilled  water.  In  this  state  it  is  in- 
soluble in  pure  water,  but  is  so  in  very  dilute  saline 
solutions  (I  per  cent.);  from  these  it  is  precipitated 
by  the  addition  of  common  salt  in  bulk.  Coagulates 
at  70°  C. 


36  Clinical  Chemistry.  [Chap.  11. 

23.  Group  III.  Fibrin. — Insoluble  in  water,  and 
in  dilute  saline  solutions.  Does  not  dissolve  in  1  per 
cent,  solutions  of  hydrochloric  acid,  but  swells  up  ; 
pepsin  added  to  this  solution  makes  the  fibrin  soluble. 
Fibrin  has  the  power  of  decomposing  hydrogen 
peroxide,  and  giving  a  blue  reaction  with  guiacum 
and  etheiial  solution  of  hydrogen  peroxide. 

Group  IV.  Modified  albiunins. — Insoluble  in 
water  and  dilute  saline  solutions,  but  soluble  in  dilute 
acids  and  alkali. 

24.  Acid  albumin  (syntonin). — Obtained  by  gradu- 
ally heating  a  solution  containing  albumin  with  a 
dilute  acid  (1  per  cent,  solution  of  strong  HlC), 
reprecipitated  by  neutralisation,  but  the  precipitate 
is  soluble  in  excess  of  the  reagent.  Its  very  dilute  acid 
solution  possesses  a  Isevo-rotatory  power  of  —  72°. 

Alkali  albumin  [casein). —  Obtained  by  heating 
solutions  of  albumin  with  dilute  alkalies,  reprecipitated 
on  neutralisation,  insoluble  in  excess,  or  in  the  presence 
of  alkaline  phosphates.  The  Isevo-rotatory  power  of 
its  alkaline  solution  prepared  from  sero-albumin  is 
—  86°,  from  egg  albumin  —47°. 

25.  Group  V.  Peptones. —  Soluble  in  water, 
not  coagulable  by  heat.  Very  diffusible,  and  pass  easily 
through  animal  membranes.  With  an  alkaline  solution 
of  cupric  sulphate  give  a  rosy  red  colour.  Precipi- 
tated by  picric  acid,  which  is  redissolved  when  warmed. 

Group  VI,  Albuminoids  or  allied  albumins, 
resembling  in  many  points  the  proteids  above  de- 
scribed in  chemical  constitution,  but  exhibit  in  their 
characteristic  reactions  considerable  difierences  among 
themselves.  They  occur  in  the  epithelial  and  con- 
nective tissues. 

26.  Mucin. — Insoluble  in  cold  water,  but  freely 
soluble  in  alkaline  solutions,  from  which  it  is  precipi- 
tated in  strong  masses  by  acetic  acid,  the  precipitate 
not  being  dissolved  by  sodium  sulphate  ;  precipitated 


Chap.  II.]        Products  OF  Metabolism.  37 

by  alcohol  and  alum,  soluble  in  excess  of  the  latter. 
Its  solutions  are  not  precipitated  by  heat  or  mercuric 
chloride,  or  potassium  ferrucyanide  and  acetic  acid. 

27.  Golafin.  —  Insoluble  in  cold  water,  but 
freely  soluble  in  hot,  fjelatinidng  when  cold.  It  is  not 
precipitated  by  acetic  acid,  but  l)y  mercuric  chloride. 
Boiling  with  acids,  or  even  prolonged  boiling,  prevents 
its  warm  solution  (jelatinisiug  when  cold. 

28.  Chondrin.  —  Soluble  in  hot  water,  gelatin- 
ising when  cold,  precipitated  by  acetic  acid,  but  the 
precipitate  is  dissolved  by  sodium  sul[)hate.  Alum 
precipitates  chondrin  in  excess. 

29.  Elasficiii. — Highly  insoluble,  even  at  high 
temperature,  its  hot  solution  does  not  gelatinise  on 
cooling,  gives  no  precipitate  with  acetic  acid. 

30.  Lardacein. —  Insoluble  in  water  and  in 
dilute  saline  solutions.  Not  acted  on  by  gastric  juice. 
Gives  a  mahogany  tinge  when  treated  by  iodine,  and 
rosy  red  by  methylanilin. 

Section  II. — Products  of  Metabolism. 

These  are  the  products  of  oxydation  of  the  non- 
nitrogenous  and  nitrogenous  constituents,  substances 
which  enter  into  the  composition  of  the  body,  and 
whose  reactions  have  been  discussed  in  the  preceding 
sections  of  this  chapter.  The  non-nitrogenous  group 
consists  chiefly  of  acids  belonging  to  the  fatty  acid 
series,  the  aromatic  groups  and  resinous  acid,  with 
some  of  their  alcohols  or  aldehydes.  The  nitrogenous 
bases,  or  amides,  are  derived  from  the  metabolism  of 
the  albuminous  principles. 

DIVISIOX    I. NOX-XITROGEKOUS. 

Group  I.  Fatty  acids. — Derived  from  the  oxyda- 
tion of  the  corresponding  alcohols  of  the  homologous 


38  Clinical  Chemistry.  [Chap.  11. 

series  of  hydrocarbon  radicals,  they  are  arranged  in 
classes  according  as  they  are  formed  by  monatomic  or 
diatomic  radicals. 

Class  I.  Monatomic  fatty  acids. — The  acids 
in  this  list  are  derived  from  the  monatomic  series  of 
homologous  hydrocarbons  by  the  oxydation  of  the 
corresponding  alcohols  in  which  one  atom  of  oxygen 
replaces  two  atoms  of  hydrogen;  thus  ethyl  alcohol  by 
oxydation  loses  two  atoms  of  hydrogen,  and  is  con- 
nected into  aldehyde ;  and  aldehyde  by  further  oxyda- 
tion becomes  acetic  acid  ;  thus, 

Ethyl  alcohol.  Aldehyde. 

C^HgO   +   O   =   O^H.O  -   H^O 

Aldehyde.  Acetic  acid. 

C,H,0    +   O    =    O^H.O^- 

31.  Formic  acid  CH2O2. — Is  a  colourless  corro- 
sive liquid,  boiling  point  100°  0.,  solid  at  1°  0. 

32.  Acetic  acid  CgH^Oy — Is  a  colourless  sharp- 
smelling  liquid  ;  boiling  point  118°  C,  solid  at  17°  C. 

Acetone. — Limpid,  colourless  liquid,  sp.  gr.  0"7921, 
with  a  peculiar  etherial  (decayed  apple)  odour.  Solu- 
tions of  acetone  give  violet-red,  with  ferric  chloride  ; 
with  iodine  and  chlorine  in  the  presence  and  alkalies 
it  is  converted  into  iodoform  and  chloroform. 

Alcohol.  —  Heated  with  a  few  drops  of  sul- 
phuric acid  and  solution  of  potassium  dichromate,  an 
emerald  green  colour  is  produced.  Nitric  acid  added 
to  alcohol,  and  this  mixture  warmed,  gives  off  fumes 
of  nitrous  ether  ;  if  to  this  a  solution  of  mercurous 
nitrate  be  added  and  heat  applied,  a  yellowish 
precipitate  will  be  thrown  down ;  this  is  mercuric 
fulminate.  A  solution  of  alcohol  heated  with  potas- 
sium hydrate  and  iodine  gives  a  yellow  precipitate  of 
iodoform. 


ciuip.  ii.j  Fatty  Acids.  39 

33.  Propionic  acid  CaHaOy  —  Is  a  colourless 
oily  lifiuid  ;  boilini,'  ]ioint  140"  C,  solid  at  20°  C. 

34.  Btityi'ic  acitl  Q^jd.,. — Is  a  mobile  colour- 
less liquid  ;  boiling  point  102°  C,  solid  at  20°  C.  ;  odour 
of  rancid  butter  ;  by  feruKaitation  lactic  acid  yields 
butyric  acid,  carbonic  acid,  and  hydrogen. 

35.  Valeric  acid  CjIIioOn. — Is  a  limpid,  colour- 
less, oily  liquid  ;  boiling  point  174°  C,  solid  at  20°  C. ; 
odour  of  valeiian. 

36.  Caproic  acid  CoHioOo.  —  An  oily  liquid 
having  the  odour  of  acid  sweat;  boiling  point  199°  C, 
solid  at  4°  C. 

37.  Capric  acid  Q,^^^^ — Is  a  greasy  oily  liquid, 
which  crystallises  at  29°  C.  in  colourless  needles, 
which  on  heating  evolve  a  goaty  odour ;  boiling  point 
236°  C. 

38.  Palmitic  acid  C10H30O2. —  Is  a  tasteless, 
white,  fatty  substance ;  melting  point  62°  C,  soluble 
in  ether  and  alcohol,  forming  acid  solutions  which  on 
concentration  deposit  white  crystalline  needles ;  in- 
soluble in  water.  With  glycerin  it  forms  three  bases 
(glycerides)  :  (1)  mono-palmatin,  (2)  di-palmitin,  and 
(3)  ti'i-palmitin ;  the  latter  is  a  constituent  of  animal 
fat,  which  mixed  with  tri-stearin  forms  margarin. 

39.  Stearic  acid  Q,^^.Jd.,. —  Is  a  white  crys- 
talline substance ;  melting  point  69"2°  C,  soluble  in 
ether  and  alcohol,  insoluble  in  water.  Like  palmitic 
acid,  it  forms  with  glycerin  three  compounds,  mono- 
stearin,  di-stearin,  and  tri-stearin ;  the  latter  is  a  con- 
stituent of  suet. 

40.  Oleic  acid  CigHsiO,- —  Is  solid  at  4°  C, 
liquid  at  14°  C.  ;  freely  soluble  in  alcohol  and  ether,  in- 
soluble in  water.  By  the  action  of  nitrous  acid  it  is 
convei'ted  into  elaidic  acid.  By  distillation  it  yields 
sebacic  acid  ;  this  distinguishes  it  from  other  fatty 
acids.  With  glycerin  it  forms  mon-olein,  di-olein,  and 
tri-olein ;  the  latter  forms  the  oily  portion  of  the  animal 


40  Clinical  Chemistry.  [Chap.  ii. 

fat.  Oleic  acid  is  in  reality  derived  from  tlie  glycerin 
series  of  homologous  hydrocarbons,  but  for  conve- 
nience is  classified  here. 

Class  II.  Diatomic  fatty  acids. — These  acids 
are  derived  from  the  "  olefine  series  of  homologous 
hydrocarbons"  by  the  oxydation  of  the  corresjDonding 
alcohols,  and  may  be  diAdded  into  two  classes,  viz., 
the  monobasic  acids  which  are  formed  by  one  atom  of 
oxygen  replacing  two  atoms  of  hydrogen  in  the  corre- 
sponding alcohol ;  and  the  dibasic  acids  which  are 
formed  by  the  replacement  of  four  atoms  of  hydrogen 
by  two  atoms  of  oxygen ;  thus  ethylene  alcohol  by 
oxydation  loses  two  atoms  of  hydrogen,  and  is  con- 
verted into  monobasic  glycollic  acid ;  and  glycollic 
acid  by  further  oxydation  loses  two  atoms  of  hydrogen 
and  becomes  dibasic  oxalic  acid,  thus  : 

Ethylene  alcohol.  Glycollic  acid. 

C,HeO,   +    O,   =   H,0    +    C,H,03 

Glycollic  acid.  Oxalic  acid. 

C2H4O3   +    O2    =--   H.O    +   C2H2O,. 

Sub-Class  (a) — Monobasic  Acids. 

41.  Cartooiiic  acid  CH2O3.  —  Colourless  in- 
odorous gas.  Specific  gravity  1-529  heavier  than  gas, 
soluble  in  an  equal  volume  of  water.  This  solution 
reddens  blue  litmus  paper,  the  red  colour  disappears  on 
drying.  Carbonic  acid  gas  passed  thi'ough  lime  water 
produces  a  white  precipitate  of  calcium  carbonate.  It 
is  best  determined  quantitatively  by  passing  it  through 
a  solution  of  potassium  hydrate  and  noting  increase  of 
weight  in  the  solution,  or  by  the  process  given  for 
estimation  of  carbonates. 

42.  Cclycollic  acid  CgH^Og.  —  This  substance 
does  not  exist  in  a  free  state  in  the  organism.  Its 
ammoniated    form,  glycocin,   conjugated    with    cholic 


ch.np.  11.]  Fatty  Acids.  41 

acid,  forms  the  glycocholic  acid  of  the  bile ;  and  with 
benzoic  acid  luiites  to  form  Ijippuric  acid.  Glycollic 
acid  is  a  syrupy  acid  liquid,  soluble  in  ether  and  alcohol, 
from  concentrated  solutions  of  which  deliquescent 
crystals,  which  uiclt  at  78°  C,  are  deposited. 

43.  L.aclic  acid  C-jHuO,... — Is  a  colourless  syrupy 
(luid  of  sharp  acid  taste;  .specific  gravity  1-21;  soluble 
in  water,  alcohol,  and  etlier.  If  distilled  at  temper- 
atures above  160°  C,  it  decomposes.  Heated  with 
sulphuric  acid  it  evolves  carbonic  oxide.  Heated  with 
nitric  acid  it  j-ields  oxalic  oxide.  Its  calcium  and  zinc 
salts-  are  characteristic.  Sarcolactic  acid  (paralactic 
and  ethylene  lactic  acids)  closely  resembles  lactic  acid 
and  is  isomeric  with  it ;  its  salts,  however,  differ  in 
crystallising  with  a  smaller  proportion  of  water,  and 
in  their  crystalline  form  ;  it  is  obtained  from  muscular 
tissue. 

46,  Licucic  acid  Q^^.f).^. — This  acid  only  exists 
in  the  body  in  its  ammoniated  form,  leucin,  from 
wjiich  it  can  be  obtained  by  heating  with  nitrous  acid. 
[See  Leucin.) 

Sub-Class  {h) — Dibasic  Acids. 

47.  Oxalic  acid  C^HjOj.  —  Crystallises  in 
pnsms ;  its  solutions  have  an  intensely  sour  taste. 
Heated  to  160°  C,  oxalic  acid  is  partially  decomposed 
into  formic  acid,  carbonic  acid,  and  water.  With 
solutions  of  lime  it  forms  the  normal  calcium  oxalate, 
a  highly  insoluble  salt,  which  is  deposited  from  urine 
usually  in  the  form  of  octohedral  crystals  of  letter- 
envelope  shape.  Solutions  of  calcium  oxalate  are 
precipitated  by  the  addition  of  alcohol.  "With  silver 
uitrate  they  give  a  white  precipitate,  soluble  in  nitric 
acid  and  ammonia ;  if  the  precipitate  be  greatly 
lieated  on  platinum  foil  it  will  decrepitate,  leaving  a 
residue  of  inctallic  silver. 


42  Clinical  Chemistry.  [Chap.  ii. 

48.  Succinic  acid  C^HgO^. — The  crystals  form 
large  rhombic  colourless  tablets  which  fuse  at  160°  C, 
and  are  soluble  in  alcohol  and  cold  water.  These 
solutions  give  a  brown  precipitate  with  ferric  chloride, 
and  white  with  barium  chloride.  Found  sometimes  in 
hydrocele  fluids  and  contents  of  ovarian  cysts. 

Group  II. — Aromatic  acid  series. 

49.  Benzoic  acid  CyHgOg. — Occurs  in  pearly 
white  crystalline  plates,  which  fuse  at  121°  C  Its 
solutions  give  reddish-brown  precipitates  with  ferric 
chloride,  and  blue  precipitates  with  cupric  acetate. 
Found  sometimes  in  stale  human  urine,  is  present  in 
the  fresh  urine  of  herbivorous  animals.  Its  chief 
interest  is  due  to  the  presence  of  its  radical  in 
hippuric  acid. 

50.  Carbolic  acid  CgHgO  (syn.  phenol). — 
Occurs  as  a  white  crystalline  mass,  melting  at  42°  C, 
and  forming  a  heavy,  oily,  corrosive  fluid  with  a  pi;n- 
gent,  smoky  odour.  It  gives  a  violet  colour  to  solutions 
of  ferric  chloride,  which  acquires  a  blue  colour  on 
exposure  to  the  air ;  a  chip  of  fir  wood  saturated  with 
phenylic  acid  and  dipped  into  dilute  hydrochloric  acid 
turns  a  deep  blue  colour.  In  carbolic  acid  poisoning 
the  sulphates  disappear  from  the  urine,  being  converted 
into  sulpho-carbolates.  Allied  to  carbolic  acid; 
taurylic,  damalitric,  and  damolic  acids  are  to  be  found 
in  minute  quantities  in  human  urine. 

Group  III.  Resinous  acids. — The  radical  of 
these  acids  has  not  been  isolated,  but  it  is  probable 
that  it  belongs  to  some  of  the  higher  aromatic  hydro- 
carbons. 

51.  Cholesteric  acid  CgHioOj. — Is  formed  when- 
ever cholesterin  is  heated  with  nitric  acid.  It  is 
a  yellow,  non-crystallisable  substance,  which  rapidly 
absorbs  moisture  from  the  air ;  it  is  soluble  in  water, 
alcohol,    and     ether.       Cholesterin    0.2^11^0   may    be 


Chap.  II. J  Nitrogenous  Bases.  43 

rt'garded  a.s  an  alcohol  of  this  series,  being  liomologons 
to  cinnyl  alcohol.  As  obtained  from  its  hot  alcoholic 
solutions  it  forms  characteristic  glistening  rhombic 
plates  with  notched  edges,  which  float  on  water ; 
extremely  soluble  in  ether.  Heated  with  nitric  acid 
it  gives  oif  yellow  acid  fumes  of  cholesteric  acid  ;  the 
residue  touched  with  annnonia  gives  a  red  colora- 
tion. Cholcsterin  may  be  mistaken  for  leucin,  but 
is  distinguished  from  that  body  by  its  solubility  in 
ether. 

52.  Cliolic  acid  Co,H,y05.  —  Occurs  in  two 
forms,  the  amorphous  and  the  crystalline.  The  former 
is  resinous  and  viscous,  very  slightly  soluble  in  water, 
but  freely  soluble  in  alcohol  and  caustic  alkalies.  In 
the  latter  the  crystals  are  octohedral  and  tetra- 
hedral ;  they  are  colourless,  insoluble  in  water,  very 
soluble  in  ether  and  alcohol ;  the  octohedral  variety 
contains  1  molecule,  the  tetrahedral  2^  molecules  of 
water;  when  heated  they  lose  this  water  of  crystallisa- 
tion and  become  disintegrated.  Cholic  acid  heated 
with  acids  at  a  temperature  of  200°  C.  loses  2  atoms 
of  water  and  is  converted  into  dyslysin  (so  named 
from  its  insolubility  in  water),  acids,  alkalies,  and 
^dcohol.  Cholic  acid  with  a  solution  of  sulphuric  acid 
and  sugar  gives  a  deep  purple  coloration  known  as 
Pettenkoffer's  test.  Conjugated  with  glycocin  and 
taurin  it  forms  the  bile  acids  glycocholic  and  tauro- 
cholic  acids. 


DIVISION    II. NITROGENOUS. 

Group  I.  Moiiaiiiides. 

53.  Olycocin  C^H^NOo,  or  amido- acetic  acid. 
Crystals  of  glycocin  are  hard  and  granular,  and  have 
a  sweet,  mawkish  taste ;  they  are  soluble  in  400  parts 
of   cold    water,    but   quite    insoluble    in    alcohol.     A 


44  Clinical  Chemistry.  [Chap.  ii. 

transient  fiery  red  colour  is  given  when  glycocin  is 
heated  with  a  strong  solution  of  caustic  potash.  A 
stream  of  nitrous  acid  passed  through  an  aqueous 
solution  of  glycocin  decomposes  it,  nitrogen  is  evolved, 
and  on  agitating  with  ether  and  evaporating  glycoUic 
acid  is  obtained.  Glycocin  is  derived  from  the 
decomposition  of  the  gelatinous  tissues ;  conjugated 
with  cholic  acid  it  forms  glycocliolic  acid,  one  of  the 
acids  of  the  bile.  This  acid  is  deposited  from  its 
alcoholic  solution  in  long  delicate  colourless  needles, 
slightly  soluble  in  cold  water  and  ether,  very  soluble 
in  alcohol  and  boiling  water.  These  solutions  are 
precipitated  by  neutral  lead  acetate ;  with  strong 
bulphuric  acid  and  sugar  they  give  a  red  coloration 
(PettenkofFer's  test). 

54  Taui'in  02117X803,  or  ethyl  amido  -  sul- 
phuric acid,  is  prepared  from  bile.  The  crystals  are 
four-sided  prisms  with  pyramidal  extremities,  insoluble 
in  ether  and  alcohol,  soluble  in  15  parts  of  cold  water; 
the  aqueous  solution  has  a  neutral  reaction.  They  are 
dissolved  by  the  mineral  acids  without  change  ;  burned 
in  air  they  evolve  sulphurous  acid  fumes;  heated  with 
potash,  ammonia  is  evolved,  and  potassiu^m  sulphate 
formed.  The  aqueous  solutions  are  not  precipitated 
by  salts  of  mercury,  copper,  or  silver.  This  substance 
is  found  in  the  bile  associated  with  cholic  acid  ;  it 
can  be  obtained  from  most  glandular  tissues,  and  from 
the  lung  tissue  and  muscular  fibre  of  the  heart. 
Taurocholic  acid  never  occurs  in  a  crystalline  form, 
but  appears  as  an  oily  resinous  fluid,  of  tawny  colour, 
very  soluble  in  alcohol  and  ether,  and  has  a  strong 
acid  reaction ;  its  aqueous  solution,  on  heating,  is 
readily  decomposed  into  taurin  and  cholic  acid ;  it 
turns  the  plane  of  polarised  light  to  the  right,  and 
gives  the  purple  reaction  with  sulphuric  acid  and  cane 
sugar.  Its  solutions  are  precipitated  by  basic  lead 
acetate. 


ciKip.  II.]  Njtrocea'ous  Basks.  45 

55.  Sarcosiii  CgH-NO.,,  or  nietliyl  glycociu,  con- 
tains one  atom  of  glycollic  acid  radical  CjHjOv,  and 
one  atom  of  methyl  OH,  replacing  two  atoms  of  II. 
It  is  not  met  with  in  the  animal  body,  its  only  interest 
being  that  it  is  a  constituent  of  kreatin,  that  body 
yielding  by  decomposition  both  urea  and  sarcosin. 

Kreatiu.  Urea.  Sarco.sin. 

C,HoN302   +  H.O  -=  CH.N.O    +    CsHjNO^. 

bQ.  Cholin  C,-H,5N02  (syn.  neurin)  may  be  re- 
garded as  ammonium  hydrate  in  which  1  atom  of  H 
is  replaced  by  1  atom  of  oxy-ethyl  C^HjO  +  3  atoms  of 

methyl  3CH3  making  /prr'x  \  ^H-O.  Cholin  is  ob- 
tainable as  a  thick  syrup,  and  has  a  powerful  alkaline 
reaction ;  soluble  in  water  and  alcohol.  Its  solution 
prevents  the  coagulation  of  albumin.  It  does  not 
exist  free  in  the  body,  but  is  a  constituent  of  leci- 
thin, protagon,  and  cerebrin. 

57.  Cysfiii  CsH-NSOj,  or  amido-sulpho-pyruvic 
acid,  an  amide  of  the  lactic  acid  series,  pyruvic  acid 
l)eing  lactic  acid  deprived  of  2  atoms  of  hydrogen. 
Deposited  from  an  ammoniacal  solution,  it  forms 
hexagonal  crystals,  which  have  a  tendency  to  overlap, 
and  whicli  acquire  a.  yellowish-green  tinge  on  exposure 
to  air.  They  are  soluble  in  alkalies  and  strong  minei'al 
acids.  Boiled  with  caustic  potash  in  the  presence 
of  lead  acetate  they  yield  a  black  precipitate  of  lead 
sulphide. 

58.  Lieucin  CgHigNOo,  or  amido  -  caproic  acid. 
— The  leucic  acid  radical  CgHuO  replacing  one  atom 

of  H  in  ammonium  hydrate;  thus    "-vi-tt    [■  0.    Leucin 

is  deposited  from  its  hot  alcoholic  solution  in  white 
shining  plates.  Slightly  soluble  in  cold  alcohol  ; 
very  insoluble  in  ether,  which  distinguishes  it  from 


46  Clinical   Chemistry.  [Chap.  ii. 

cliolesterin,  which  it  closely  resembles  in  appearance, 
Yery  soluble  in  boiling  water.  Leucin  is  interesting 
physiologically  as  being  one  of  the  antecedents 
of  urea,  and  pathologically  from  its  presence  in  the 
urine  in  certain  diseases  of  the  liver. 

59.  Tyi'osin  CgHnNOg  is  probably  amido- 
propionic  acid  Qi^^QS.^^Q^  in  which  1  atom  of  H  is 

C3H,    I 
replaced  by  oxy-phenol  CeHgO  to  make  CgHjO  V  Oj. 

nhJ 

The  crystals  are  fine  needles,  which  sometimes  cluster 
to  form  stellate  groups,  or  packs  to  form  rounded 
balls.  They  are  sparingly  soluble  in  cold  water  and 
alcohol ;  soluble  in  boiling  water  and  in  acid  and 
alkaline  solutions.  War-med  with  strong  nitric  acid 
they  become  yellow ;  the  residue,  if  touched  with 
hydrochloric  acid,  becomes  red,  if  with  ammonia,  brown. 
Millon's  reagent  (mercuric  and  mercurous  nitrate)  gives 
a  red  coloration  resembling  that  given  by  proteid 
with  the  same  reagent.  Ty rosin,  when  it  appears  in 
the  urine,  is  always  associated  with  leucin,  though  this 
latter  body  may  be  present  without  tyrosin.  It  is 
found  in  small  quantities  in  the  spleen  and  pancreas, 
and  is  one  of  the  products  of  the  action  of  tryjDsin  on 
albuminous  matters. 

60.  Hippiu'ic  acid  CgHgNOg,  or  benzyl  amido- 
acetic  acid,  containing  radicals  of  benzoyl  and  glycocol, 
and  may  be  written  thus  0^1150(0^114)^03.  The  crystals 
are  semitransparent  rhombic  prisms  ;  almost  insoluble 
in  cold  water  and  ether,  soluble  in  boiling  water  and 
solution  of  sodium  phosphate.  Boiled  with  strong 
hydrochloric  acid  it  is  decomposed  into  glycocin  and 
benzoic  acid.  Hippuric  acid  is  monobasic  and  gives 
buff- coloured  precipitates  with  ferric  salts.  It 
occurs  as  a  minute  normal  constituent  of  human 
urine,  and  in  larger  quantities  among  herbivorous 
animals. 


Chap.  II.]  N/TROGENOUS  Bases.  47 

61.  Liecifliin  C^iITj^iNPOb  is  an  amorphous  waxy 
substance,  very  liysroscopic ;  soluble  in  ether  and 
alcohol,  is  procipitattMl  from  the  so'ution  by  platinic 
chloride  with  excess  of  alcohol.  Lecithin  is  decom- 
posed by  boiliniij  with  alkalies  into  glycerin-phosphoric 
acid,  stearic  acid,  and  cholin.  Frotm/on  has  been  con- 
sidered as  a  mi.Kture  of  lecithin  and  cerebrin,  but 
the  recent  researches  of  Gamgee  seem  to  show  that 
it  is  a  definite  chemical  body ;  he  gives  the  formula 
CuinH-ji^^NsPOs^.  Cerebrin  is  a  nitrogenous  body  free 
from  phosphorus.  Some  doubt  still  exists  as  to  its 
composition.  According  to  Gaingee,  protagon,  which 
cannot  be  separated  by  the  action  of  solvents  into  a 
non-phosphorised  cerebrin  and  a  phosphorised  body, 
can,  however,  by  the  action  of  caustic  baryta  be  made 
to  yield  non-phosphorised  bodies. 

Group  II.     Diamides. 

62.  Urea  CH^NoO,  or   carbamide,    and    may  be 

CO" ) ' 
represented  as    H    J-  N,,  in  which  the  dibasic  radical 

H   J 

of  carbonic  acid  has  replaced  two  atoms  of  hydrogen ; 

or  as  CO  s  -ytt'  "^  which  2  atoms  of  amidogen  NHg 

have  taken  the  place  of  2  atoms  of  hydroxyl  HO.  Urea 
is  also  isomeric  with  ammonium  carbamate  and  am- 
monium cyanide.  Urea  crystallises  in  colourless 
four-sided  prisms  which  melt  at  120°  C.  Very  soluble 
in  cold  water,  and  its  solutions  are  neutral  to  test 
paper.  Heated  to  1 50°C. ,  urea  is  converted  into  bi-uret 
and  cyanuric  acid.  With  niti'ic  acid  urea  forms  nitrate 
of  urea,  which  crystallises  out  in  shining  rhombic 
plates ;  these  crystals  are  less  soluble  than  urea 
crystals,  therefore  when  the  urine  is  concentrated  they 
are   often   formed    on    the    addition    of    nitric   acid. 


48  Clinical  Chemistry.  [Chap.  11. 

Oxalic  acid  also  forms  oxalate  of  urea,  which  is 
deposited  as  fine  powdery  crystals.  Mercuric  nitrate 
in  alkaline  solutions  forms  with  urea  an  insoluble 
compound  CON2H4,  4H9O1.  Hypobromous  acid  de- 
composes urea  into  water,  carbonic  acid,  and  nitrogen. 

COMPOUND  UREAS. 
Sub-class  A.     Monureides. 

6.3.  Kreatiu  C^HgNgO^  +  H^O.  —  This  sub- 
stance in  contact  with  baryta  water  decomposes  into 
urea  and  sarcosin  (page  45).  The  crystals  are  oblique 
rhombic  prisms  slightly  soluble  in  cold  water  and 
alcohol,  very  soluble  in  hot  water,  insoluble  in  ether. 
The  solutions  ai'e  neutral,  and  have  an  extremely  bitter 
taste.  Acted  on  by  sulphuric  acid,  it  is  converted 
into  kreatinin.  Kreatin  is  chiefly  found  in  the  juice  of 
flesh,  and  is  undoubtedly  an  antecedent  of  urea. 

Ki'ea,tiiiiii  C4Hj]Sr30  is  formed  from  the  fore- 
going by  dehydration.  It  is  an  extremely  powerful 
base,  gives  an  alkaline  reaction  with  test  paper, 
and  forms  well-defined  basic  double  salts  with  zinc 
chloride  and  silver  nitrate. 

Sub-Class  B.     Diureides. 

64.  Uric  acid  C5H4]Sr403. —  There  is  still  some 
doubt  as  to  the  exact  constitution  of  uric  acid ;  it  is, 
however,  represented  by  the  hypothetical  formula  as 
consisting  of  one  radical  of  tartronic  acid  and  two  of 
urea,  thus  : 

Tartronic  acid.  Urea.  Uric  acid. 

C3H4O5  +  2(CH4N,0)  =  an^N^Oa  +  4H,0. 

From  this  it  is  held  that  uric  acid  is  tartronyl 
cyanamide,  four  molecules  of  amidogen  being  replaced 


Chap.  II.]  IS/ITROGENOUS   BaSES.  49 

by  two  of  cyanogen,  and  two  by  the  radical  of  tartronic 

(  C,H,03 
acid  ;  thus  Nj*;  ON  2         As  deposited  from  acid  solu- 

tions  it  occurs  in  rliombic  tablets  of  very  variable  form. 
It  is  extremely  insoluble  in  water  and  acid  solutions, 
very  soluble  in  alkaline  solutions.  Uric  acid  is  di- 
basic, and  forms  with  bases  both  neutral  and  acid  salts, 
of  which  the  sodium,  potassium,  and  ammonium  are 
of  the  n)ost  interest ;  tliese  are  all  very  insoluble  in 
water,  but  less  so  than  uric  acid.  When  in  solution, 
if  these  salts  are  decomposed  by  the  addition  of 
concentrated  nitric  acid,  the  uric  acid  is  separated  in 
an  amorphous  and  hydrated  form,  in  which  it  is 
rather  more  soluble  than  in  its  crystalline  state.  This 
amorphous  form  of  uric  acid  is  frequently  observed 
when  concentrated  nitric  acid  is  added  to  urine 
when  testing  for  albumin,  and  has  been  erroneously 
described  as  precipitated  acid  urates,  which  may  be 
thrown  down  when  dilute  acid  is  used,  if  the  urates 
were  previously  in  the  neutral  form.  The  character- 
istic test  for  uric  acid  is  the  viurexide  reaction,  the 
jiurple  colour  developed  when  the  crystals  are  heated 
with  nitric  acid,  and  the  residue  touched  with  am- 
monia. By  oxydation  uric  acid  yields  alloxan  and 
urea ;  mesoxalic  acid  and  urea,  allanturic  acid  and 
urea;  parabauic  acid  (which  is  oxalyl  ui-ea),  tartronyl 
urea  or  dialuric  acid. 

65.  Xaufhin  CsH^N^Oo.— The  constitution  of 
this  body  is  unkno^Ti ;  uric  acid  treated  with  sodium 
amalgam  yields  xanthin  and  hypoxanthin.  Xanthin 
forms  Avhite  scales  resembling  beeswax,  sometimes 
deposited  from  urine  in  minute  lemon-shaped  plates ; 
these  dissolved  in  dilute  hydrochloric  acid,  and  the 
solution  slowly  evaporated,  yield  hexagonal  and  pris- 
matic crystals.  Very  insoluble  in  water  (1  in  1,500), 
freely   soluble  in  dilute   acids  and  alkalies.     J-Teated 


5©  Clinical  Chemistry.  [Chap.  ii. 

with  nitric  acid,  and  the  residue  moistened  whilst 
still  hot  with  liquor  potassse,  a  purple-red  colour  is 
developed.  A  constituent  of  a  rare  form  of  urinary 
calculus  and  gravel. 

%%.  Hypoxanthin  C5H4N4O  (syn.  sarcine). — 
Is  a  white  imperfectly  crystalline  powder,  rather  more 
soluble  in  water  than  xanthin.  Found  in  the  spleen, 
thymus,  muscular  tissue,  medulla  of  bones,  and  blood 
of  leuceemic  patients. 

67.  Allantoin  €4116^403  can  be  formed  from 
uric  acid  by  boiling  with  lead  peroxide.  Forms 
colourless  hard  glassy  prisms  of  neutral  reaction. 
Soluble  in  cold  water  (1  in  160).  Boiled  with 
potassium  hydrate  it  yields  potassium  oxalate.  Con- 
stituent of  allantoic  fluid  and  foetal  urine. 

68.  Carnin  C7HgN"403. — Has  been  discovered  in 
Liebig's  extract  of  meat ;  it  can  be  converted  into 
hypoxanthin  by  the  action  of  bromine. 

69.  Ouanin  CgHslSrsO.  —  A  yellowish -white 
powder  nearly  insoluble  in  water,  but  sokible  in 
dilute  acids  and  alkalies.  By  oxydation  with  potassium 
permanganate  is  converted  into  urea,  oxalic  acid, 
oxy-guanin.  Is  a  normal  constituent  of  the  semi- 
solid excrement  of  birds.  It  has  been  sometimes  met 
with  in  the  liver,  pancreas,  and  spleen,  but  does  not 
appear  to  be  a  constant  product. 

DIVISION    III. VEGETO-ALKALOIDS. 

These  bodies  are  supposed  to  be  compound 
ammonias,  and  act  as  powerful  bases  ;  are  the  active 
principles  of  certain  plants.  Those  of  highly  poison- 
ous nature  are  enumerated  here,  as  they  may  be  intro- 
duced into  the  animal  body  either  accidentally  or 
with  criminal  intent,  when  their  detection  becomes  a 
matter  of  consequence.  A  group  of  animal  alkaloids, 
the  result  of  putrefactive  changes  in  the  tissues,  have 


Chnp.  II.]  Alkaloids.  51 

recently  been  discovered,  and  are  named  ptoamin.es  ; 
they  correspond  in  their  general  reactions  with  the 
vegeto-alkaloids. 

70.  Morphine  Ci,H,(,NO,  +  Hp.— The  crystals 
are  colourless  prisms,  very  slightly  soluble  in  water 
(1  in  1,000  cold;  1  in  500  hot).  Very  soluble  in 
hot  alcohol.  The  salts  are  more  soluble  in  water 
than  the  base.  It  gives  an  indigo-blue  coloration, 
with  a  neutral  solution  of  ferric  chloride.  With 
sti'ong  niti'ic  acid  forms  a  deep  orange-yellow  com- 
])ound.  Concentrated  sulphuric  acid,  with  a  trace  of 
nitric  acid,  gives  a  violet-purple  colour.  Morphine 
decomposes  iodic  acid  with  the  liberation  of  iodine. 

71.  Strycliiiine  C,Ji^J>i X>^. — The  crystals  are 
extremely  small  brilliant  octohedra,  transparent,  and 
colourless.  Slightly  soluble  in  water  (1  in  6,000  cold; 
1  in  2,500  hot),  more  soluble  in  chloroform.  The 
solutions  have  an  intensely  bitter  taste  (perceptible 
1  in  1,000,000).  With  concentrated  sidpburic  acid, 
and  a  fragment  of  potassium  dichromate,  a  deep  violet 
tint  is  produced,  gradually  fading  on  exposure.  Solu- 
tions of  strychnine  {-j-^jyjj  grain)  injected  under  skin 
often  produce  violent  tetanic  spasms  and  death. 

72.  Brucine  C^HofiNgO^  -f  4H2O.— More  soluble 
in  water  than  strychnine,  and  is  readily  soluble  in 
alcohol.  Is  distinguished  from  it  by  the  bright  red 
colour  given  when  touched  with  nitric  acid. 

73.  Curarine  C,oH,.=i]Sr. — Yery  soluble  in  water 
and  alcohol.  Nitric  acid  gives  a  purple  coloration. 
Concentrated  sulphuric  acid  colours  it  blue,  and  if 
potassium  dichromate  is  added,  changes  to  violet 
slowly  fading  to  yellow.  In  this  test  it  resembles 
strychnine,  but  is  distinguished  from  that  body  by 
its  ready  solubility  in  water. 

74.  Atropine  Ci^Ho-jlSTOs. — Ciystallises  in  colour- 
less needles,  slightly  soluble  in  water,  very  soluble 
in    chloroform.     With    concentrated    sulphuric    acid 


52  Clinical  Chemistry.  [Ckap.  ii. 

no  coloration  in  tlie  cold,  but  on  heating  a  yellow- 
tinge  is  developed,  and  on  adding  water  a  rose- 
like odour  is  given  off.  Solutions  containing  trace  of 
atropine  have  highly  poisonous  effects  on  frogs. 

75.  Ptoamimes. — This  name  has  been  given  to 
bodies  which  have  been  detected  in  exhumed  corpses, 
closely  resembling,  in  their  chemical  reactions  and 
physiological  effects,  the  vegetable  alkaloids.  Whilst 
some,  however,  act  as  powerful  poisons,  others  are 
inactive,  and  a  few  actually  counteract  the  effect  of 
poisonous  substances.  Spica,  in  the  liquid  from  a 
suppurative  peritonitis,  obtained  bodies,  some  of 
which  were  oily  and  volatile,  with  a  strong  alkaline 
reaction  and  capable  of  forming  crystalline  salts,  and 
having  the  odour  of  conine.  The  chloroform  extract 
was  extremely  poisonous  in  its  actions  on  frogs,  and  in 
its  physiological  effect  resembled  that  of  curarine. 
Sonnenschein  has  found,  in  an  anatomical  maceration 
fluid,  an  alkaloid  resembling  atropine  in  its  action. 
Hanke  has  shown  that  the  physiological  action  of 
strychnine  in  bodies  long  buried  may  be  masked  by 
ptoamines.  A  body  resembling  Sonnenschein's  al- 
kaloid has  been  found  in  bodies  of  patients  dying 
from  typhus  fever.  It  is  interesting  to  observe  that 
in  many  instances  of  death  resulting  from  poisonous 
food,  the  patient  showed  marked  typhus  symptoms. 
It  appears  that  these  bodies  are  generally  produced  in 
substances  which,  after  brief  exposure  to  air,  are 
buried  or  excluded  from  air,  as  in  corpses,  tinned 
meat,  etc.,  and  that  then  they  are  found  in  the  most 
internal  portion.  It  is  of  importance  to  discover  the 
reactions  which  distinguish  these  bodies  from  the 
vegeto-alkaloids,  but  the  question  is  often  one  of 
extreme  difficulty.  It  has  been  stated  that  potassium 
ferrocyanide  is  a  reliable  reagent,  since  ptoamines 
reduce  it,  whilst  the  vegeto-alkaloids  have  no  reaction 
on  it.     The  test  is  applied   as  follows  : — The  extract 


Chap.  II. 1  Colouring  Matjeks.  53 

is  converted  into  a  sulphate,  and  a  few  drops  of  solu- 
tion of  K.,FeCyrt  added  ;  if  a  ptoamineis  present,  Prus- 
sian blue  will  be  foriiiod  on  the  additiou  of  a  few  drop.s 
of  ferric  chloride.  No  reaction,  however,  is  given 
with  a  vegcto-alkaloid,  except  morphine  and  veratrine ; 
these,  however,  can  bo  detected  by  their  special  tests. 

INDIGO    GROUP. 

76.  Iiidol  CttHjN. — A  crystalline  substance  which 
is  the  starting  point  of  the  indigo  group.  It  occurs 
in  the  body  as  one  of  the  products  of  pancreatic  di- 
gestion, and  is  said  to  give  the  characteristic  odour 
to  the  fieces.  The  addition  of  salicylic  acid  to  pan- 
creatic juice  stops  its  formation  from  albuminoids  ; 
and  it  has  been  found  that  under  the  administration  of 
the  acid  the  quantity  of  indol  decreases  exactly  in 
proportion  as  the  quantity  of  phenol  increases.  Very 
dilute  nitrous  acid  gives  a  red  colour  in  solution  of 
indol. 

In(lig:o  CjeHioNoCj. — This  substance,  which  is 
derived  commercially  from  the  indigo/era,  is  some- 
times met  with  in  sweat  and  urine,  giving  rise  to  a 
bluish  colour.  It  has  been  met  with  as  a  constituent 
of  urinaiy  calculus  [Med.  Path.  Soc.  Trans.,  vol.  xxix., 
p.  157).  The  source  of  indigo  in  the  body  is  un- 
doubtedly from  indol  formed  by  the  decomposition  of 
albuminoids  by  pancreatic  digestion,  since  indican 
C^Ji^.^ X)^i,  or  glucoside  of  indigo,  is  found  in  the 
urine  of  animals  after  the  subcutaneous  injections  of 
indol,  also  after  ligature  of  the  small  intestine,  and  also, 
according  to  Senator,  in  obstructions  and  other  afiec- 
tions  of  the  intestines  in  disease.  The  indol  being  pro- 
bably converted  into  indican  in  the  alkaline  blood,  but 
deposited  as  indigo  when  it  comes  in  contact  with  the 
acid  urine.  However  this  may  be,  indican  out  of 
the  body  always  yields  indigo  as  one  product  of  its 


54  Clinical  Chemistry.  [Chap.  ii. 

decomposition,  and  indi-glucin,  a  sweet,  non-ferment- 
able substance  which  reduces  Fehling's  solution.  Uro- 
xanthin,  a  colouring  matter  found  in  the  urine,  strongly 
resembles  indican  ;  it  does  not,  however,  yield  indigo- 
blue  under  the  action  of  acids. 

78.  Colowrmg^  matters  of  lnunan  toody 
are  the  colouring  matters  of  the  blood,  haemoglobin 
and  its  derivatives.  The  bile  pigments,  bilirubin, 
biliverdin,  bilifuscin,  biliprasin,  urobilin.  The  urinary 
pigments,  uroxanthin  or  indican,  and  urobilin  and  a  • 
black  pigment  melanin,  found  normally  in  the  choroid 
and  in  the  skin  of  negro,  and  pathologically  in  melanotic 
tumours,  in  the  urine,  and  as  a  deposit  in  the  lungs. 
For  the  reaction  of  the  various  pigments,  the  reader 
is  referred  to  chapters  on  blood,  bile,  and  urine. 

Section  B. — Inorganic  Constituents. 

79.  Hydrocliloa-ic  acid  (HCl).  —  Chlorine  in 
the  body  is  chiefly  found  in  combination  with  the  alka- 
line oxides  of  soda  and  potash.  These  salts  are,  however, 
variously  distributed;  thus,  for  example,  in  1000  parts 
blood  corpuscles,  we  find  3-67  parts  of  potassium  with 
only  a  trace  of  sodium  chloride,  whilst  in  the  plasma 
there  is'  only  -36  parts  of  potassium  chloride,  and  as 
much  as  5 '54  parts  in  the  1000,  The  chlorides  appear 
to  fulfil  the  following  purposes  in  the  economy:  (1) 
by  furnishing  the  hydrochloric  acid  for  digestion 
(2Na^HP0,  +  3CaCl  =  Ca32P04  +  4NaCl  +  2HCI  ; 
Maly) ;  (2)  by  aiding  the  metabolic  processes  going 
on  in  the  body,  an  increased  ingestion  of  common  salt 
being  followed  by  increased  excretion  of  urea.  Sodium 
chloride  is  found  in  great  abundance  in  all  cellular 
growths,  as  in  cartilage,  mucus,  etc.  In  certain 
diseases  attended  with  increased  cell  formation,  as  in 
cancer,  in  pneumonia  with  exudation,  and  in  puru- 
lent   discharges,  sodium  chloride   is  present  in  large 


Chap.  II.]  Inorganic  Acids.  55 

quantities  in  the  morbid  products,  and  consequently 
there  is  a  sensible  diminution  in  the  quantity  excreted 
by  the  urine.  H'dmr  nitrate  gives,  in  extremely  dilute 
solutions,  a  faint  haze  ;  in  stronger  solutions  a  white 
cloudy  precipitate  ;  nitric  acid  will  not  cause  these  to 
dissolve ;  they  are  soluble,  however,  in  ammonia,  but 
on  nitric  acid  being  added  to  the  ammoniacal  solution, 
the  silver  chloride  is  again  precipitated. 

80.  Hydrofluoric  acid  HF.  —  United  with 
calcium  as  calcium  Huoride,  is  found  in  minute  quan- 
tities in  the  bones  and  teeth,  occasionally  in  blood,  milk, 
and  urine.  The  ash  treated  with  strong  sulphuric  acid, 
and  gently  heated  in  a  glass  vessel,  the  glass  becomes 
corroded.      Large  quantities  of  ash  must  be  employed. 

81.  Phosphoric  acid  H3PO4. — Phosphorus  is 
one  of  the  most  important  of  the  inorganic  constitu- 
ents of  the  body,  and  is  widely  distributed.  In  com- 
bination it  is  found  as  a  component  of  the  complex 
nitrogenous  fats,  lecithin,  etc.  In  its  oxydised  form  it 
occurs  as  tribasic  phosphoric  acid.  In  combination 
with  soda  and  potash  it  forms  the  alkaline  phosphates, 
the  neutral  salts  of  which  (Na^HPO^),  together  with 
the  alkaline  carbonates,  gives  to  blood  its  alkaline  re- 
action ;  the  acid  salts  NaH2P04  gives  urine  its  acid 
reaction.  Bone  earth  is  tricalcic  phosphate  Ca32P04. 
Magnesium  phosphate  associated  with  calcium  phos- 
phate is  found  in  all  animal  tissues  and  fluids,  but  to 
a  less  extent ;  in  the  excreta,  however,  the  magnesium 
is  relatively  more  abundant  than  the  calcium  salt. 
From  this  it  has  been  inferred  that  the  magnesium 
salt  is  less  required  by  the  organism,  and  consequently 
is  not  so  long  retained  as  the  calcium  salt,  and  also 
that  less  is  absorbed  by  the  intestinal  canal.  Few 
questions  in  scientific  medicine  afford  less  facts  for 
generalisation  than  the  variations  in  the  excretions 
of  phosphoric  acid  by  the  urine  in  disease.  Physio- 
logy can  only  tell  us  that  the  element  phosphorus  is 


56  Clinical  Chemistry.  [Chap.  ii. 

al)Solutely  essential  for  the  growth  and  nutrition  of  the 
tissues,  but  cannot  explain  its  role.  Pathologically 
we  find  {a)  excess  of  phosphoric  acid  accompanied  by  a 
proportionate  increase  in  the  elimination  of  urea  ;  (6) 
excess  of  phosphoric  acid  without  a  proportionate  in- 
crease. In  the  first  instance  the  increase  is  probably 
due  to  increased  tissue  metabolism  generally ;  in  the 
second,  probably  only  the  nervous  system  is  involved. 
The  compound  known  as  triple  phosphate,  or  ammonio- 
magnesiuin  phosphate  P04Mg(]SrH4)  +  6H2O,  is  met 
with  in  ammoniacal  urines  ;  this  salt  combined  with 
calcium  phosphate  forms  the  basis  of  one  of  the  most 
frequent  forms  of  phosphatic  calculus,  known  as  the 
fusible  calculus.  Phosphoric  acid  gives  a  yellow  preci- 
pitate with  silver  nitrate  soluble  in  both  nitric  acid  and 
ammonia.  A  yellow  precipitate  is  given  with  ammo- 
nium molyhdate  in  nitric  acid.  An  acid  solution  of 
uranic  nitrate  is  decomposed  by  phosphoric  acid,  and 
uranic  phosphate  is  precipitated  ;  this  latter  gives  no 
stain  with  ferrocyanide  of  potassium  test-paper,  which 
uranic  nitrate  does  ;  upon  this  fact  the  process  for 
estimating  quantitatively  phosphoric  acid  is  based. 
{Q.v.  Urine.) 

82.  SulpliuFic  acid  H^SO^. — Sulphur  is  found 
in  most  protein  bodies,  and  in  many  products  of 
their  metabolism,  as  cystin  and  taurin.  It  is  also 
largely  introduced  into  the  body  with  vegetable  sub- 
stances. Only  a  small  portion  of  the  sulphur  in  the 
body  passes  out  as  sulphuric  acid,  a  considerable  part 
being  discharged  either  unoxydised  or  only  partially 
Dxydised  by  the  bowels,  and  some  by  the  skin  and 
ej)idermal  appendages.  It  is  thus  difficult,  from  the 
increase  or  diminution  of  sulphuric  acid  in  urine,  to 
form  an  estimate  of  the  degree  of  metabolism  of  the 
sulphur  compounds  in  the  body.  The  sulphuric  acid 
in  the  urine  is  for  the  most  part  combined  with  potash 
an.d  to  some  extent  with  lime.     About  0*4  grain  of 


Chap.  II.]  Inorganic  Bases.  57 

sulphur  also  passes  into  urine  in  a  partially  oxydised 
state  in  the  twenty-four  hours.  The  sulphates  oj*e 
detected  in  acid  solutions  by  the  addition  of  barium 
chloride  or  nitrate,  which  throws  down  a  dense  cloud 
of  barium  sulphate. 

8.3.  Sulplio-cyanatc  of  potassium  CNKS. 
— A  trace  of  this  substance  is  found  in  saliva.  Petten- 
kofler  believes  it  to  be  derived  from  decomposition 
occurring  in  the  ca\'ity  of  the  mouth,  being  derived 
from  urea  and  sulphate  of  potash.  Dr.  S.  Fenwick, 
however,  has  [Med.-Chir.  Trans.,  1882)  endeavoured  to 
show  that  the  presence  of  sulf)ho-cyanate  in  saliva  is 
not  due  to  accidental  causes,  but  is  regulated  by  the 
operation  of  general  laws,  and  the  amount  present 
varies  considerably  in  disease.  The  chief  ])oint  of 
practical  importance  is  its  relation  to  medico-legal 
inquiries  in  cases  of  opium  poisoning,  since  meconic 
acid  gives  the  same  reaction  with  ferric;  c/n/orisWe  as  the 
sulpho-cyanate,  viz.,  a  cherry-red  ;  this,  however,  dis- 
appears on  the  addition  of  mercuric  chloride,  which  is 
not  the  case  with  the  colour  pz'oduced  by  meconic  acid. 

84.  Liimc  CaO.  —  Lime  must  be  considered  as 
one  of  the  chief  mineral  constituents  of  the  body.  As 
phosphate  of  lime,  it  ranks  next  to  water  in  the  im- 
portance of  its  physical  properties  to  the  organism. 
Its  salts  constitute  (54  per  cent,  of  the  weight  of 
the  skeleton,  viz.  :  calcium  phosphate,  51 '04  ;  calcium 
fluoride,  1'9  ;  and  calcium  cai-bonate,  11  "4  per  cent. 
In  blood  the  calcium  salts  are  in  excess  in  the  plasma, 
1000  parts  yielding  "298  part  of  lime,  whilst  the  same 
weight  of  corpuscles  give  only  "094.  In  muscular  tissue 
lime  is  present,  ranging  from  "230  to  "311  part  in  a 
1000.  Lime  salts  are  tolerably  abundant  in  the  gastric 
juice,  about  1-48  of  calcium  phosphate  in  the  1000. 
Maly  believes  the  hydrochloric  acid  of  the  gastric  juice 
is  derived  from  the  decomposition  of  chloride  of  cal^ 
cium(2Na,HP0,  +  sCaCl  =  Ca32P0,  +  4XaCl  +  2HCI). 


58  Clinical  Chemistry.  [Chap.  11. 

Only  a  small  proportion  of  tlio  lime  injected  is 
excreted  with  the  urine.  In  experiments  on  dogs  it 
was  found  that  when  calcium  chloride  was  given  by 
the  mouth  nearly  all  the  lime  was  passed  off  by  the 
bowel  as  carbonate,  only  a  small  increase  in  the  ex- 
cretion of  lime  by  the  urine  being  noted,  and  that  as 
phosphate.  The  chlorine  appeared  in  combination 
with  sodium  as  chloride  of  sodium.  In  rickets  it  has 
been  said  there  is  a  great  increase  in  the  quantity 
of  lime  salts  excreted  in  the  urine,  but  the  fact  is  by 
no  means  established ;  recent  observations  have  ac- 
tually found  a  diminution,  which  was  most  marked 
when  the  disease  was  at  its  height.  It  is  probable 
that  the  idea  that  an  increase  of  lime  excreted  took 
place  in  rickets  was  due  to  the  mere  deposition  of  the 
earthy  salts  being  taken  for  excess.  The  urine  of  rickety 
children  is  frequently  alkaline,  and  consequently  is 
often  turbid  from  deposited  calcium  phosphate.  Local 
deposits  of  calcium  carbonate  are  frequently  met  with 
in  tissues  which  have  suffered  from  general  impairment 
of  vitality,  or  from  diminished  nutritive  supply.  In 
these  cases  it  is  probable  that,  owing  to  the  escape 
of  the  free  carbonic  acid,  which  keeps  this  salt  in 
solution,  from  the  stagnated  fluids,  the  calcium  salt  is 
precipitated,  and  on  account  of  the  degeneration  of  the 
tissues  is  not  taken  up  by  them.  Salts  of  lime  form 
the  insoluble  portion  of  the  ash ;  to  obtain  them  in 
solution  they  must  be  dissolved  in  as  small  a  quantity 
as  possible  of  dilute  acetic  acid.  Ammonium  oxalate 
added  to  this  solution  gives  a  copious  white  precipitate 
of  calcium  oxalate.  Mineral  acids  should  not  be  used 
to  dissolve  the  ash,  as  the  calcium  oxalate  would  re- 
dissolve  if  the  acid  was  in  excess.  The  amount  of 
lime  present  is  best  determined  by  weight.  For  this 
purpose  the  insoluble  portion  of  the  ash  is  weighed, 
and  the  w-eight  recorded.  It  is  then  dissolved  with 
acetic  acid,  and  the  solution  diluted  by  the  addition  of 


Chap.  II.]  InORCANIC   JSasES.  59 

about  ton  times  its  woiglit  of  distilled  water.  To  this 
solution  add  saturated  solution  of  ammonium  oxulate, 
and  allow  to  stand  for  twelve  hours.  Filter  through  a 
filter  the  weight  of  whose  ash  is  known.*  The  pre- 
cipitate in  the  filter  consists  of  calcium  oxalate.  The 
filtered  solution  is  magnesia,  which  should  be  set  aside 
for  determination  of  that  substance  if  required.  Wash 
the  precipitate  on  the  tilter  with  distilled  water.  Dry 
over  water-bath  till  the  filter  and  contents  cease  to 
lose  weight.  Place  the  filter  and  contents  in  a  small 
platinum  capsule  with  cover,  whose  weight  is  known; 
beat  till  whole  is  reduced  to  white  ash.  When  cool 
convert  the  lime  into  sulphate  by  the  addition  of  a 
few  drops  of  sulphuric  acid.  Again  heat  carefully, 
covering  to  prevent  loss.  Weigh  the  capsule  when 
cold.  Now,  when  the  weight  of  the  ash  of  the  filter 
and  the  weight  of  the  capsule  are  deducted  from  the 
total  weight,  we  have  the  weight  of  sulphate  of  lime, 
and  to  calculate  this  as  caustic  lime,  we  multiply  by 
0-4118. 

85.  Magnesia  MgO.  —  Magnesium  phosphate 
associated  with  calcium  phosphate  is  found  in  all  the 
animal  tissues  and  fluids,  but  in  smaller  quantities. 
Little  is  knowTi  as  to  the  purpose  it  fulfils  in 
the  economy.  The  chief  clinical  interest  attaching 
to  it  is  from  it  forming,  as  triple  phosphate,  a  variety 
of  urinary  gravel,  and  a  calculous  crust  in  cei'tain 
morbid  conditions  of  the  urinary  organs,  which  induce 
the  formation  of  A'olatile  (ammonia)  alkali.  The 
triple  phosphate  is,  however,  generally  associated 
with  calcium  phosphate,  the  mixture  of  the  two  salts 
forming  a  mass  readily  fusible  under  the  blow- 
pipe. Neutral  solution  of  magnesia  throws  down  a 
bulky  gelatinous  precipitate  with  ammonia.  The  ad- 
dition of  sodium  fhospliate  to  a  magnesian  solution 

*  This  is  done  by  incinerating  a  filter  of  the  same  size  and 
weight  as  tlie  one  used,  and  weighing  the  ash. 


5o  Clinical  Chemistry.  [Chap.  n. 

gives  rise  to  a  white  precipitate  of  magnesian  phos- 
phate, whilst  the  addition  of  ammonia  throws  the 
ammonio-magnesium  phosphate.  Magnesia  is  esti- 
mated by  weight.  The  ash  is  treated,  in  the  first 
instance,  as  directed  for  lime.  The  filtrate,  obtained 
after  the  removal  of  the  precipitate  caused  by  am- 
monium oxalate  (lime  oxalate),  is  treated  with  excess 
of  ammonia,  and  allowed  to  stand  twelve  hours. 
The  resulting  precipitate  is  collected  on  a  filter,  the 
weight  of  whose  ash  has  been  previously  ascer- 
tained ;  the  filter  is  then  dried  till  it  ceases  to  lose 
weight.  When  dry  it  is  to  be  placed  in  a  small 
platinum  capsule  whose  weight  is  known,  and  heated 
to  a  white  heat  till  a  white  glassy  mass  is  left  at  the 
bottom  of  the  capsule.  This  is  magnesium  pyro- 
phosphate. Weigh  the  capsule  when  cold,  and  by 
deducting  the  weight  of  the  ash  of  the  filter  and 
the  weight  of  the  capsule  from  the  total  weight,  the 
result  gives  amount  of  magnesium  pyrophosphate  ; 
by  multiplying  this  weight  by  0-3604  we  get  the 
amount  of  magnesia  present  as  oxide. 

86.  Ammonia  NHg.  —  Ammonia  in  a  free 
state  is  sometimes  found  in  urine ;  generally,  however, 
it  is  in  the  form  of  carbonate,  the  result  of  ureal  de^ 
composition.  It  has  been  detected  in  the  breath  of 
typhus  patients.  The  chief  salt  of  interest  it  forms 
is  ammonium  urate,  a  constituent  of  the  urinary 
excretion  of  insects,  reptiles,  and  birds,  and  is  fre- 
quently met  with  as  a  urinary  deposit  in  human 
beings. 

87.  Potash  KHO.  —  This  body,  with  soda, 
forms  the  soluble  portion  of  the  ash.  Potash  is 
widely  distributed  throughout  the  body,  but  in  very 
variable  proportions.  It  is  more  abundant  in  the 
solid  tissues  .and  the  corpuscles  than  in  the  secre- 
tions and  plasma  of  the  blood ;  in  this  respect 
being   the   very   opposite    of   the   soda   salts.      The 


cnap.  II.]  Inorganic  J^ASEs.  6i 

potash  salts  seem  to  have  a  greater  activity  than 
those  of  sodium.  Ringer  has  found  them  more 
poisonous,  as  far  as  their  action  on  the  heart  is 
concerned,  than  the  sodium  salts.  It  is  said  that 
a  dog  fed  on  nothing  but  Liebig's  extract  dies 
sooner  than  a  dog  not  fed  at  all,  on  account  of 
the  potash  salts  exerting  a  poisonous  influence.  Dr. 
Garrod,  some  years  ago,  found  that  the  amount  of 
potash  salts  in  urine  were  diminished  in  scurvy, 
and  suggested  that  this  disease  was  in  some  way 
connected  with  a  deficiency  of  this  base  in  the 
body,  and  that  dietaries  of  persons  afi'ected  with  the. 
disease  were  deficient  in  potash.  Furtlier  examination 
has  not  shown  this  to  be  correct,  since  peas  and  other 
articles  of  a  sailor's  diet  have  been  shown  to  contain 
a  sufficiency  of  potash.  I  have,  however,  recently 
confirmed  Dr.  Garrod's  observation  as  to  the  defi- 
ciency of  potash  in  the  urine  of  scorbutic  patients, 
but  I  believe  that  the  diminution  is  not  due  to 
diminished  ingestion,  but  to  the  base  being  withheld 
by  the  blood  in  order  to  maintain  its  alkalinity, 
which  has  been  impaired  by  the  withdrawal  of  the 
alkaline  carbonates  supplied  by  fresh  meat,  vege- 
tables, and  fruits.  Solutions  of  potash  salts  give, 
with  platinum  bi-chloride,  when  sKghtly  acidulated 
with  hydrochloric  acid,  a  yellow  crystalline  precipi- 
tate of  potassium  platinic  chloride.  The  estimation 
of  potassium  and  sodium  can  be  conveniently  done 
together,  and  will  be  considered  in  the  next  para- 
graph. 

88.  Sodiiiin  NaO  is  more  abundantly  met  with 
in  fluids  than  in  the  solid  textures  of  the  body,  in  this 
case  being  the  reverse  of  the  potassium  salts.  Thus, 
we  find  in  blood  ])lasma  5  "540  parts  of  sodium  chloride, 
1-532  parts  of  soda,  and  •271  part  of  sodium  phosphate, 
as  compared  with  -359  part  of  potassium  chloride  and 
•281  of  potassium  sulphate  in  1000,     Whilst  in  the 


62  Clinical  Chemistry.  [Chap.  ii. 

blood  corpuscles  the  reverse  obtains  ;  for  in  1000  parts 
"we  have  3 "6 79  potassium  chloride,  2-343  potassium 
phosphate,  "132  potassium  sulphate,  against  "341  of 
soda  and  -635  sodium  phosphate.  The  acidity  of  the 
urine  is  chiefly  due  to  acid  sodium  phosphate 
NaH2P04.  The  bile,  too,  is  particularly  rich  in 
soda  salts,  containing  about  2-5  per  cent,  of  sodium 
chloride  and  6  per  cent,  bile  salts,  in  the  form  of 
glycocholate  and  taurocholate  of  soda.  The  action 
of  soda  salts  on  the  excitability  and  contractility  of 
the  heart  is  decidedly  less  than  that  of  potash  salts, 
but  it  is  nevertheless  marked.  ^The  chief  clinical 
interest  attaching  to  salts  of  soda  is  the  formation  of 
gouty  tophi  and  calculous  infarcts  in  the  tubules 
of  the  kidney,  composed  of  sodium  urate.  A  con- 
centrated solution  of  sodium  salt  gives  a  white 
crystalline  precipitate  with  antimioniate  of  potash. 
Soda  salts  also  give  a  characteristic  yellow  tinge  to  the 
blow-pipe  flame.  Potassium  and  sodium  can  be  deter- 
mined quantitatively  by  the  same  operation.  Dissolve 
a  definite  quantity  of  ash  in  boiling  distilled  water. 
Filter.  Bring  the  filtrate  up  to  60  cc.  by  the  addition 
of  distilled  water,  or  diminish  by  evaporation  to  that 
bulk.  Of  this  quantity  take  30  cc.  (which  will  repre- 
sent half  the  quantity  of  the  soluble  salts  in  the  ash), 
add  a  few  drops  of  ammonia  and  ammonium  carbonate. 
Set  aside  for  twelve  hours,  filter  through  a  very  small 
filter.  Acidulate  the  filtrate  with  a  few  drops  of 
hydrochloric  acid,  and  place  it  in  a  platinum  capsule 
of  known  weight.  Evaporate  to  dryness,  and  then 
heat  gradually  to  redness  to  drive  ofi"  ammoniacal 
salts.  Weigh  when  cool ;  deduct  weight  of  capsule  ; 
result  gives  weight  of  potassiu'in  and  sodium  chlorides, 
of  half  the  amount  of  ash  originally  taken  for  ex- 
periment. To  estimate  the  potash,  dissolve  the 
residue  in  the  platinum  capsule  in  as  little  water 
as    possible,   and   then  add  an  alcoholic  solution  of 


Chap.  II.  1  IXOKCANIC    BaSES.  63 

platinic  liichloride  till  tlio  solution  acquires  a  tlcep 
yellow  colour  ;  evaporate  to  luiar  dryness,  and  then 
add  50  cc.  of  absolute  alcohol  and  10  of  ether. 
Set  aside  for  twenty-four  hours,  frequently  stirring. 
Collect  precipitate  on  weighed  filter ;  wash  it  with 
alcohol ;  dry  it.  Weigh ;  deduct  weight  of  filter. 
The  remainder  gives  amount  of  potassium  platino- 
chloridc  (100  parts  of  which  equals  30"/)l  potassium 
chloride).  Now,  as  we  have  learnt  the  combined 
weight  of  the  potassium  and  sodium  chlorides  from 
the  first  y)art  of  the  process,  we  have  only  to 
deduct  the  Aveight  of  the  now  ascertained  potassium 
chloride  from  the  weight  of  the  two  chlorides,  to  find 
the  difference,  loJiich  is  the  aniount  of  the  sodium 
chloride.  To  get  the  amount  of  potash  and  soda  we 
have  to  multiply  the  weight  of  potassium  chloride  by 
0-6317  and  the  sodium  chloride  by  0-5302.  The 
result  being  the  amount  of  potash  and  soda  in  the 
ash,  in  the  30  cc.  of  the  dissolved  ash,  or  exactly  half 
the  amount  of  the  whole  ash  dissolved  in  the  first 
instance.  The  object  of  dividing  the  original  solu- 
tion being,  of  course,  to  reserve  a  portion  in  case  of 
accidents,  or  a  desire  to  check  the  process  at  any 
point 

89.  Iron  FoOj. —  Traces  of  iron  are  met  with 
in  the  ash  of  most  tissues  and  fluids ;  as  a  proto- 
chloride  in  the  ash  of  gastric  juice,  and  as  a  phosphate 
in  muscular  and  splenic  juice.  Combined  with 
globulin  as  htemoglobulin,  it  forms  the  colouring 
matter  of  the  blood.  Preyer  from  an  average  of  eleven 
cases  gives  0-056  grm.  of  iron  and  13-45  grms.  of 
haemoglobin  in  100  grms.  of  human  blood.  It  is 
probable  that  the  iron  of  the  eftete  blood-corpuscles 
passes  away  with  the  bile,  recent  observations 
tending  to  show  that  the  coloui-ing  matters  of  the  bile 
are  produced  from  hoeniatin  by  reduction,  due  to  the 
action  of  the  bile  acids  on  haemoglobin.     When  iron 


64  Clinical  Chemistry.  [Chap.  ii. 

salts  are  taken  an  increase  of  this  metal  is  found  in 
the  bile.  The  salts  of  iron  are  met  with  as  proto  or 
ferrous  salts,  and  per  or  ferric  salts.  The  former  give 
white  })recipitates  with  caustic  alkalies  and  light  blue 
precipitates  with  potassium  ferrocyanide ;  the  latter 
a  reddish-brown  precipitate  with  caustic  alkalies  and 
a  deep  blue  precipitate  with  potassium  ferrocyanide. 
The  amount  of  iron  in  the  ash  of  any  tissue  or  fluid  is 
determined  by  the  standard  solution  of  potassium 
permanganate.  This  was  formerly  the  only  method 
by  which  the  amount  of  iron  ia  blood  could  be  deter- 
mined. Since,  however,  the  proportion  of  iron  to 
haemoglobin  has  been  ascertained,  the  metal  can  be 
estimated  quantitatively  through  the  determination  of 
the  haemoglobin,  either  by  Hoppe  Seyler's  or  Gower's 
method.  The  procedure  by  these  methods  will  be 
treated  more  conveniently  when  we  consider  the 
variation  occurring  in  the  amount  of  haemoglobin  in 
disease.  (Vide  Blood.) 

90.  Silica  SjOj. — Silica  is  a  constituent  of  the 
epidermal  tissues ;  it  is  nearly  always  present  in  the 
faeces,  and  occasionally  in  the  blood,  bile,  and  urine. 
Silica  may  be  obtained  from  the  ash  of  any  of  the 
substances  in  which  it  is  present,  by  fusing  the  ash 
with  eight  times  its  weight  of  sodium  carbonate,  a.nd 
boiling  the  mass  in  water ;  on  the  addition  of  hydro- 
chloric acid  the  silica  is  partially  precipitated  as  a 
gelatinous  mass.  The  acid  solution  is  now  evaporated, 
and  the  residue  treated  with  some  more  hydrochloric 
acid  and  dried.  The  silica  will  then  be  left  as  a  white 
insoluble  powder, 

91.  l-ead  Pb;  arsenic  AsgOg;  copper  Cu. 
—  These  substances  are  only  incidentally  present 
in  the  tissues,  and  are  apparently  in  no  way  necessary 
to  the  maintenance  of  their  functions.  It  has  been 
stated  that  arsenic  and  copper  are  constantly  present 
in  minute  quantities  in  the  human  body.     The  method 


Chap.  III.]  Blood.  65 

of  sepiu-iitiug  learl  and  arsenic  from  the  tissues  and 
fluids  in  cases  of  poisoning  is  detailed  in  the  chapter 
on  morbid  disestiou  and  on  urine. 


CHAPTER   III. 

BLOOD — CHYLE — LYMPH — MILK. 

Examination    of    morbid    blood.  —  Of    all 

branches  of  pathological  chemistry,  less  advance  has, 
pei'haps,  been  made  in  determining  the  changes 
which  blood  undergoes  in  disease  than  in  aviy  other 
direction.  Some  excuse  may  be  offered  for  this 
apparent  neglect,  in  the  ditticulty  of  obtaining  blood 
in  sufficient  quantity  for  analysis,  a  difficulty  that  did 
not  exist  in  days  when  bleeding  was  general  and 
regarded  as  part  of  the  ordinary  treatment.  Also,  the 
methods  of  research  until  recently  have  been  very 
defective.  The  study  of  the  chemistry  of  morbid  blood, 
however,  must  be  seriously  undertaken  before  we  can 
expect  to  judge  of  the  eftects  produced  by  even 
primary  alteration  of  the  blood  in  disease.  For  as  yet 
how  little  do  we  know  of  the  variations  that  daily  and 
hourly  occur  in  the  chemical  composition  of  normal 
blood,  and  what  is  the  action,  physical  as  well  as 
chemical,  that  each  of  its  constituent  elements  has  on 
the  albumins,  fats,  .salts,  and  water  that  compose  the 
tissues,  and  how  far  excess  or  diminution  of  these 
constituents  influences  oxydation  and  nutrition  in 
the  body. 

9l'.  Variation  between  tlie  water  and 
solids.— Specific  jp'avity. — The  following  figures 
give  approximatively  the  composition  of  normal  blood 
in    100    parts.       Water,    79-5;    solids,    20 -5 ;    serum 

F 


66  Clinical  Chemistry.  [Chap.  iii. 

albumin,  7  "2;  fibrin,  0-21;  hsemogiobin,  11 '5;  fatty- 
matters,  0'18;  extractives,  0'32;  ash,  0'81.  100  parts 
of  blood  serum  contain  water  90 "5  parts ;  solids, 
9 '6.  The  proteids  varying  from  8  to  9,  and  the 
fat  extractives  and  salts  from  2  to  1.  100  parts 
of  wet  blood-corpuscles  yield  water,  56  "5;  solids,  43 '5; 
hsemogiobin,  41-1;  other  proteids,  3-9;  fats,  chiefly 
cholesterin  and  lecithin,  "37.  The  proportion  of  water, 
however,  varies  considerably,  and  probably  ranges  from 
76  to  80  in  healthy  blood  under  the  influence  of 
normal  physiological  conditions,  the  ingestion  of  fluids, 
of  solid  food,  and  the  activity  of  the  renal  and 
cutaneous  excretions.  The  proportion  of  water  to  the 
solids  can  be  ascertained  by  evaporating  a  small 
quantity  of  blood  in  a  weighed  platinum  capsule,  till 
it  ceases  to  lose  weight.  Then,  if  z  represents  the 
weight  of  the  blood  evaporated  and  y  the  loss  sus- 
tained by  evaporation,  then  ' =  x  the  propor- 
tion of  water  in  1000  parts.  The  specific  gravity- 
is  ascertained  by  means  of  a  small  flask  fitted  with 
perforated  stopper  for  the  insertion  of  a  thermometer. 
The  fiask  is  then  filled  M'ith  distilled  water  at  15°  C, 
and  weighed  ;  it  is  then  emptied  and  dried,  and 
then  filled  with  defibrinated  blood  at  the  same 
temperature  and  again  weighed.  Then  if  a  represents 
the  weia;ht  of  the  distilled  water  and   h  the  weight 

of  the  defibrinated  blood,  —  =  the  specific  gra^vity  of 

the  blood ;  thus,  if  the  weight  of  the  flask  filled  with 
distilled  water  is  25-573  grains,  and  the  weight  of  the 
flask  with  defibrinated   blood  is  27  "160  grains,  then 

— -    =    1'060.     As,  however,  liquids    expand   and 

25-57a  '      ^  ^ 

contract  by  alteration  of  temperature,  a  coi-rection  is 

necessary  if  the  two  fluids  are  weighed  at    di-fferent 

temperatures.    Practically,  however,  if  both  weighings 


Chap.  III.)  Reaction  of  Blood.  67 

are  conducted  at  the  same  time  and  in  Hk;  same  room 
very  little  diflereiice  occurs ;  if  it  docs,  it  can  be 
corrected  by  plunging  the;  bottle  in  warm  water  if  the 
temperature  be  too  low,  or  into  cold  water  if  too  high. 
The  following  gives  the  maximum  and  minimum 
percentage  amount  of  water  in  different  diseases  as 
recorded  by  trustworthy  observers.  Normal  blooil, 
78-8—80;  scurvy,  84-9— 83-5;  chloro.sis,  8G-8— 81-8; 
cancer  of  liver,  88'7  ;  chronic  Bright  s  disease,  80  8 — 
88*7;  puerperal  eclamp.sia, 77*8 — 80;  diabetes  mellitus, 
79-4— 80  2  ;  cholera,  74-0 — 75-0.  There  are  many 
analyses  of  blood  in  acute  diseases,  but  their  value  is 
impaired  by  the  fact  that  they  were  generally  made 
after  repeated  venesections,  which  of  course  in  itself 
lendei-s  the  blood  more  watery. 

93  Reaction. — Acid  and  acid  salts  are  continu- 
ously entering  the  blood.  (1)  Tliey  may  be  introduced 
into  the  body  from  without  in  the  food.  The  quantity, 
however,  thus  derived  under  ordinary  conditions  is 
comparatively  small,  since  nearly  the  whole  of  the 
saline  constituents  of  the  food  are  alkaline,  or  become 
so  by  conversion  in  the  system.  Still,  a  small  quantity 
of  acid  sodium  phosphate  is  derived  from  the  juice  of 
flesh,  and  this  passes  no  doubt  unchanged  into  the 
blood.  (2)  Acid,  too,  is  formed  in  the  alimentary 
canal  fi'om  fermentative  decomposition  of  the  saccharine 
matters  taken  with  the  food,  or  of  the  amylaceous 
principles  that  have  been  converted  into  sugar.  (3) 
Lastly,  acid  is  generated  in  the  tissues  of  the  body. 

In  spite,  however,  of  this  constant  entrance  of  acid 
into  it,  the  blood  of  the  living  body  is  always  alkaline, 
no  doubt  because  the  chief  acid  salt  (sodium  bicai'- 
bonate)  has  an  alkaline  reaction.  What  the  degree  of 
alkalescence  of  noi-mal  blood  is  has  not  been  determined, 
but  it  is  probable  that  it  has  certain  definite  limits 
which  caimot  be  passed  in  either  direction  without 
causing  disturbance  of  healthy  nutrition.    In  fact,  great 


68         '  Clinical  Chemistry.  [Chap.  hi. 

difficulty  is  experienced  in  reducing  the  alkaline 
reaction  of  the  blood.  Hoffmann,  wlio  fed  pigeons  for 
a  considerable  time  on  food  yielding  only  an  acid  ash 
(yolk  of  egg),  found  that  however  great  the  tendency 
of  uric  acid  and  of  the  acid  salts  of  [)hosphoric  acid  to 
combine  with  bases,  yet  these  were  not  withdrawn 
from  the  alkaline  blood,  but  were  evidently  withheld 
to  maintain  its  alkalinity.  Loscar,  by  introducing 
diluted  mineral  acids  into  the  stomach,  succeeded  in 
reducing  the  alkalescence  of  the  blood,  but  not  con- 
siderably, and  the  conclusion  he  arrived  at  was  that 
the  organism  retained  free  alkali  with  great  energy. 
In  some  of  his  experiments  the  quantity  of  acid  intro- 
duced into  the  stomach  would  have  made  the  whole 
animal  acid  if  it  had  been  absorbed  and  excreted 
again.  From  this  Loscar  infers  that  the  organism 
possesses  certain  "  regulative  mechanisms "  which 
maintain  the  equilibrium  between  the  acids  and 
alkaline  bases  in  the  system.  These  experimental  facts 
seem  to  be  borne  out  by  what  occurs  in  scurvy.  That 
disease,  as  has  been  well  estabhshed,  is  brought  about 
by  the  prolonged  and  complete  withdrawal  of  the 
organic  vegetable  acids  and  their  salts  from  the  dietary 
of  those  affected.  These  organic  salts,  as  is  well 
known,  by  oxydation  in  the  blood  yield  alkaline  carbo- 
nates. Now,  the  alkaline  carbonates  are  the  salts 
chiefly  concerned  in  maintaining  the  alkalescence  of 
the  blood,  and  it  appears  when  these  are  largely  with- 
drawn, as  happens  when  scurvy  is  induced,  the  proper 
degree  of  alkalescence  of  the  blood  is  maintained  with 
difficulty,  and  in  order  to  secure  it  some  other  alkaline 
salt  is  retained  instead  of  being  excreted.*  Thus,  I 
found,  after  the  withdrawal  of  fresh  vegetable  food  for 
eighteen  days,  the  total  quantity  of  phosphoric  acid 
Tiassed  in  the  twenty-four  hours  was  slightly  reduced, 
whilst  the  phosphoric  acid  in  combination  with  the 
*  "  General  Pathology  of  Scurvy,"  Lewis.    1877. 


Chap.  III.]  Reaction  of  Bi.oon.  69 

alkaline  oxides  was  reduced  nearly  one  half.  Again,  in 
a  case  of  scurvy,  it  was  found  that  the  alkaline  phos- 
phates increased  rapidly  on  the  resumption  of  an 
antiscorbutic  diet,  although  the  amount  of  phosphoric 
acid  ingested  was  the  same  in  scorbutic  and  antiscor- 
butic rations  respectively  ;  these  two  facts  pointing  to 
the  conclusion  that  the  alkaline  phosphates  are  retained 
in  the  system  when  the  alkaline  carbonates  are  with- 
drawn, and  discharged  when  these  are  again  supplied. 
All  experiments  made  on  animals  with  a  view  to  reduce 
the  alkalinity  of  the  blood  or  to  neutralise  it  have 
ended  sooner  or  later  in  the  death  of  the  animal;  and  if 
the  process  has  been  a  slow  one,  the  definite  patho- 
logical changes  will  be  found  to  have  occurred  in  the 
blood  and  tissues,  closely  i-esembling  the  changes  found 
in  the  Ijodies  of  patients  dying  from  scurvy,  viz.  dis- 
solution of  the  blood  globules,  ecchymosis  in  the  heart, 
blood  stains  in  the  mediastinum,  gums,  and  mucous 
surftices ;  whilst  the  muscular  structure  of  the  heart, 
and  the  muscles  generally,  as  well  as  the  secreting  cells 
of  the  liver  and  kidneys,  become  gi'anular  and  even 
distinctly  fatty.  Lastly,  Dr.  Gaskell  has  shown, 
experimentally,  that  a  dilute  alkaline  solution  acts  upon 
the  muscular  tissues  of  the  heai^t  so  as  to  produce  a 
powerful  contraction,  whilst  dilute  acid  solutions  pro- 
duce an  opposite  effect,  and  that  the  muscles  of  the 
smaller  arteries  are  acted  upon  in  the  same  w-ay. 
These  facts  seern  to  point  to  the  conclusion  that  one 
factor  at  least  upon  which  the  constriction  of  the 
nniscles  both  of  heart  and  arteries  depend,  is  the 
alkalinity  of  the  fluid  surrounding  them.  It  is  not 
unreasonable,  therefore,  to  surmise  that  vai'iations  of 
the  degree  of  alkalinity  would  not  be  unlikely  to  lead 
to  disturbances  of  circulation  and  so  effect  a  secondary 
chemical  influence  on  nutrition,  as  well  as  a  direct  one. 
The  two  salts  chiefly  concerned  in  the  maintenance 
of  the  alkalinity  of  blood  are  neutral  sodium  phosphate 


70  Clinical  Chemistry.  [ch.ip.  hi. 

Na^^HPO^,  and  acid  sodium  carbonate  (bicarbonate) 
NaHgCOg ;  it  is  owing  to  this  composition  that  the 
seeming  paradox  of  the  separation  of  acid  secretion, 
such  as  urine  and  the  gastric  juice,  from  the  alkaline 
blood  can  be  explained.  [Vide  §§  8,  107,  and  134.) 
No  precise  observations  have  been  made  as  to  varia- 
tions in  the  alkalinity  of  the  blood  in  disease.  Garrod 
has  found  it  diminished  in  a  case  of  gout ;  it  has  also 
been  found  lessened  in  the  blood  sei'um  in  chronic 
Bright's  disease  and  in  cholera.  This  particular  branch 
of  enquiry  ought  to  yield  abundant  information  to  the 
clinical  enquirer,  with  respect  to  the  nature  of  such 
diseases  as  acute  rheumatism,  gout,  scurvy,  and  dia- 
betes mellitus.  The  serum  from  a  blister  may  be  used, 
or  sufficient  blood  for  the  purpose  can  be  readily  ob- 
tained by  means  of  the  artificial  leech.  This  should  be 
detibrinated,  and  placed  in  a  beaker.  Then  from  aMohr's 
burette,  a  standard  solution  of  crystallised  tartaric  acid, 
1  cc.  of  which  is  equivalent  to'OOi  grm.  sodium  hydrate, 
is  to  be  added.  This  solution  is  gradually  dropped 
into  the  beaker  containing  the  blood,  and  a  drop  trans- 
ferred after  each  addition  by  means  of  a  glass  rod  to  a 
plaster  of  Paris  plate,  stained  with  a  solution  of  blue 
litmus.  The  addition  of  the  acid  solution  is  continued 
till  a  faint  red  stain  is  given  to  the  plate  by  the  drop 
placed  in  it.  The  number  of  cubic  centimetres  of  the 
standard  solution  employed  to  neutralise  the  blood, 
multiplied  by  -004,  gives  the  alkalinity  of  the  quantity 
of  blood  taken  in  terms  of  sodium  hydrate.  In 
preparing  the  plate  care  must  be  taken  to  obtain  the 
plaster  of  Paris  free  from  alkaline  reaction,  and  to 
remove  any  alkali  fi-om  the  litmus.  This  is  done  by 
thoroughly  dissolving  20  grammes  of  litmus  in  150 
cubic  centimetres  of  water,  and  allowing  the  solu- 
tion to  stand  twenty-four  hours,  then  filtering.  The 
precipitate  is  again  dissolved  in  250  centimetres  of 
distilled  water,  and  allowed  to  stand  for  twenty-four 


Chap.  111.1  J'lliRlN   OF   Bf.OOD.  7 1 

liours  ;  it  is  then  divided  into  two  equal  portions. 
Una  is  treated  with  dihite  acid,  added  drop  by 
drop  by  means  •  of  a  ghiss  rod  till  the  solutioii  is 
faintly  red ;  it  is  then  added  to  the  other  portion. 
The  plaster  of  Paris  plates  are  then  soaked  in 
the  resulting  violet-blue  solution.  It  is  absolutely 
necessary  to  prepare  the  plate  before  obtaining  the 
blood,  since  by  keeping,  even  a  few  hours,  the 
alkalinity  of  the  blood  is  diminished. 

94.  Fibrin. —  Wlieu  blood  is  drawn  from  the 
body  it  separates  into  clot  and  serum.  The  former 
consists  of  fibrin,  holding  in  its  meshes  the  blood 
corpuscles  ;  these  latter  can  be  removed  by  washing 
the  clot  Avith  a  gentle  stream  of  water.  The  amount  of 
fibrin  in  normal  blood,  as  according  to  recent  analyses, 
ranges  from  -21  to  '23  parts  in  100.  The  older 
analyses  state  it  as  "31  to  '34.  In  many  diseases  it  is 
considerably  increased.  The  following  gives  some  of 
the  more  reliable  observations  :  Acute  bronchitis,  from 
•43  to  -63  in  100  parts.  Pneumonia,  -40  to  1'05. 
Pleurisy,  before  effusion,  "58  to  "59  ;  pleurisy,  after 
effusion,  -40  to  "48.  Acute  rheumatism,  the  mean 
of  forty -three  observations,  '67.  Puerperal  convul- 
sions, '44  to  'GO.  Heart  disease,  mean  of  twenty-four 
cases,  "34  ;  advanced  heart  disease,  '25,  mean  of  thirty- 
one  cases.  Chloi'osis,  mean  of  nine  cases,  -29.  Scurvy, 
•45  to  -65.  Diabetes,  -19  to  -24.  Phthisis,  mean  of 
twenty-two  analyses,  -44.  Puerperal  fever,  -43  to  -51. 
The  so-called  "  buffy  coat,"  which  sometimes  forms 
on  the  surface  of  the  clot  in  blood  drawn  in  certain 
diseases,  does  not  necessarily  depend  on  the  amount 
of  fibrin  present,  but  on  delay  in  the  act  of  coagu- 
lation, and  the  tendency  of  the  red  corpuscles  to 
aggregate  together,  which  is  generally  observable 
in  the  inflammatory  state.  These,  therefore,  have 
a  tendency  rapidly  to  subside,  leaving  the  white 
corpuscles,   which    are   lighter   in    the   upper  portion 


72  Clinical  Chemistry.  [Chap.  iii. 

of  the  clot,  and  these  give  it  the  buffy  appearance.  The 
antecedents  of  fibrin  in  the  blood  are  paraglobulin,  or 
fihrino-plastic  substan  ce,  ajid  fibrinogen  ;  whilst  for  the 
conversion  of  fibrinogen  into  fibrin  outside  the  body, 
the  action  of  a  third  body,  the  fibrin  ferment,  is 
required  (§  21).  The  addition  of  this  latter  body  to 
fluids  containing  fibrino-plastic  and  fibrinogen  imme- 
diately brings  about  coagulation,  as  may  be  seen  some- 
times in  its  addition  to  chylous  urine,  in  which  there 
is  but  little  coagulum,  causing  at  once  an  abundant 
separation.  This  is  also  occasionally  observed  with 
hydrocele  fluid.  Fibrin  is  estimated  quantitatively 
in  uncoagulated  blood  by  drawing  the  blood  directly 
into  a  bottle,  whose  weight  has  been  accurately  deter- 
mined, fitted  with  a  perforated  stopper,  through  which 
a  rod  is  inserted,  to  which  is  attached  a  brush  of  fine 
wire.  When  a  sufficiency  of  blood  has  passed  into 
the  bottle,  the  rod  with  attached  whisk  is  stirred 
round  and  round  for  a  quarter  of  an  hour,  when 
the  fibrin  will  attach  itself  to  the  wires  composing  the 
brush.  The  outside  of  the  bottle  is  now  to  be  care- 
fully cleaned  and  dried,  and  then  weighed ;  the 
addition  to  the  original  weight  of  the  bottle  and 
apparatus  gives  the  amount  of  b.iood  employed.  Now 
pour  the  contents  of  the  bottle  into  a  muslin  strainer, 
and  with  a  pair  of  delicate  forceps  pick  ofi'  from  the 
wires  the  adhering  fragments  of  fibrin,  and  place  them 
on  the  muslin  strainer,  wash  most  thoroughly  with 
cold  water  till  they  are  completely  freed  from 
adhering  corpuscles  or  serum,  and  subsequently  wash 
with  ether.  Then  remove  them  to  a  weighed  platinum 
capsule,  and  dry  over  water-bath  till  it  ceases  to  lose 
weight,  and  let  it  cool  in  chamber  of  balance,  over  a 
beaker  of  strong  sulphuric  acid.  Then  weigh ;  the 
increase  of  weight  in  the  platinum  capsule  gives  the 
amount  of  fibrin.  This,  however,  contains  some 
inorganic  residue  j  in  order  to  obtain  the  fibrin  pure 


Chap.  III. I     COLOURIXC    AfATTER    OF    Bl.OOP.  7.^ 

it  must  be  incinerated.  For  tliis  purpose  the  capsule 
is  heated  till  only  a  white  ash  is  left,  and  is  iigaiix 
weighed.  The  loss  in  weight  deducted  from  the 
weight  of  the  fibrin  before  incineration  gives  the 
amount  of  pui-e  fibrin.  Supposing  the  original  weight 
of  blood  was  31-2  grammes,  and  the  weight  of  pure 
fibrin     obtained     from     this     'OGG     grannnes,      then 

TT^^ —  =  -21   granunes   or   fibrin    m   100  parts  01 

blood.  When,  however,  we  have  to  deal  with  blood 
already  coagulated  we  have  to  cleanse  the  already 
separated  filjrin  from  the  blood  corpuscles,  a  proceeding 
of  considerable  difficulty.  This  is  done  by  weighing 
100  centimetres  of  blood  in  a  beake}-,  and  draining  off 
tlie  serum  through  a  linen  strainer,  washing  well 
with  cold  water;  after  a  while  fold  the  strainer,  as 
a  bag,  over  the  contents  ;  wash  with  water  and 
knead  the  contents  till  all  the  corpuscles  are  re- 
moved, and  the  clot  decolorised.  Then  transfer  the 
filaments  by  means  of  a  delicate  pair  of  forceps  to  the 
platinum  capsule,  and  proceed  as  above. 

95.  Colcui'iiig  matter  of  the  blood  is  con- 
tained in  the  red  corpuscles.  These  are  minute 
discoidal  bodies,  nearly  transparent,  of  a  yellowish 
colour,  varying  in  diameter  from  -g  oVo  ^'^  toW  °^  ^^''■ 
inch,  the  average  being  put  at  -stj^o  (or  7-9  micro- 
millimetre),  and  abouty^ioy  inch  (1-8  micromillimetre) 
in  thickness.  The  human  blood  corpuscles  contain  no 
nucleus.  In  fresh  unaltered  blood  the  surfaces  of 
the  red  corpuscles  are  bi- concave,  and  form  peculiar 
rolls,  like  coins  adhering  together.  Under  certain 
abnormal  conditions,  or  when  the  blood  is  diluted 
with  saline  solutions,  as  sodium  chloride,  sodium 
sulphate,  magnesium  sulphate,  etc.,  the  corpuscles 
lose  their  smooth  circular  outline,  shrinking,  and 
becoming  crenate.  On  the  other  hand,  wlien  placed 
in  fluids  of  low   density  they  swell  up,  and  become 


74  Clinical  Chemistry.  [Chap.  in. 

bi-convex  and  globular,  and  may  even  burst.  The 
red  corpuscles  are  formed  of  a  delicate  membrane^ 
stroma  (oikoid,  Briicke),  which  contains  the  colouring 
matter  (zooid)  hsemoglobulin,  cholesteriu,  lecithin,  and 
inorganic  salts.  The  stroma  is  the  colourless  portion 
of  the  living  blood  corpuscle ;  it  is  insoluble  in  water 
and  serum,  and  in  sodium  chloride  solutions,  but 
freely  soluble  in  ether,  chloroform,  caustic  soda, 
ammonia,  and  in  solutions  of  the  bile  acids  and  urea. 
The  stroma  appears  to  combine  with  the  hsemoglobin, 
and,  so  to  speak,  fixes  it,  but  tlie  union  is  very  feeble, 
and  very  slight  disturbing  influences  set  free  the 
colouring  matter.  The  hsemoglobin  in  the  living 
blood  is  combined  with  an  alkali,  probably  potash,  to 
keep  it  in  solution,  as  otherwise  it  is  very  insoluble, 
and  would  crystallise  out. 

One  hundred  parts  of  human  dried  corpuscles  con- 
tain hajmogiobin,  86-79;  proteids,  12-24:;  lecithin, 
0-72;  cholesterin,  0-25  (HoppeSeyler).  The  corpuscles 
may  be  obtained  for  analysis  by  rapidly  defibrinating 
blood,  and  then  adding  to  it  ten  times  its  volume  of 
a  10  per  cent,  solution  of  common  salt,  and  setting 
aside  in  a  cool  place,  when  the  corpuscles  will  be 
deposited.  They  are  then  to  be  collected  on  a  filtei', 
and  washed  thoroughly  with  sodium  chloride  solution 
till  thoroughly  free  from  serum.  The  mass  is  then 
placed  in  a  weighed  caj)sule  and  dried ;  the  weight 
after  drying  represents  the  amount  of  corpuscles 
present  in  a  certain  quantity  of  blood. 

(a)  Clinical  determination  of  hcemoglohin.  —  In 
disease  the  amount  of  hsemoglobin  varies  consider- 
ably. According  to  Quincke  the  following  are  some 
of  the  chief  deviations  observed  :  Taking  11 -5  to  12-0 
to  represent  the  percentage  amount  of  hsemoglobin  in 
normal  blood,  then  in  a  case  of  cirrhosis  of  liver,  with 
epistaxis,  it  was  10"1  per  cent.;  in  chlorosis,  5*3, 
after  taking  ii'on,    9*92;    in  leucocythsemia,    5-8 ;    in 


Chnp.  III.]    Co  LOUR  I  KG  Matter  of  Blood.  75 

Brin[ht's  disease,  granular  kidney,  8'5  and  10-60  ;  with 
larire  fatty  kidney,  10-30  and  10-70;  in  diabetes 
niellitus,  14-4  ;  in  phosphorus  poisoning,  14-9.  For 
clinical  purposes  the  amount  of  haemoglobin  present 
in  blood  may  be  estimated  by  means  of  the  number  of 
blood  corpuscles,  and  their  depth  of  colour.  This  is 
done  by  counting  first  (by  means  of  the  hpemocyto- 
meter),  the  number  of  corpuscles  in  a  small  quantity 
of  blood,  and  then  comparing  the  colour  of  the  same 
blood  with  a  tint  of  a  solution  of  hfemoglobin  of 
known  strength.  For  this  purpose  the  instruments 
devised  by  Dr.  Gowers*  are  the  ones  generally 
employed.  First  of  all  the  number  of  the  corpuscles 
has  to  be  determined.  This  is  done  by  the 
hamocyfomeler.  The  proceeding  is  as  follows :  5 
(u1)ic  millimetres  of  blood  are  drawn  into  a  capillary 
tube  from  a  puncture,  by  means  of  a  spear-pointed 
needle  in  the  finger,  and  blown  into  a  cup-like  cell 
containing  99.5  cubic  millimetres  of  solution  of 
sodium  sulphate  (sodium  sulphate  and  distilled  water 
added  till  the  specific  gravity  is  1-02-5),  measured  oil' 
by  means  of  a  specially  graduated  pipette.  The 
contents  of  the  cell  are  to  be  well  mixed  with  a  little 
spatula,  and  then  one  drop  is  to  be  placed  in  the  cell- 
like depression,  with  ruled  squares  of  —  millimetre 
each  on  the  floor  of  the  slide,  to  which  springs  are 
attached  to  secure  a  cover  glass.  The  slide  is  then 
placed  in  the  stage  of  a  microscope,  the  lens  focussed 
to  bring  the  squares  into  view.  A  few  minutes  are 
allowed  to  let  the  corpuscles  sink  on  to  the  squares, 
and  then  the  number  contained  in  10  squares  is 
counted  ;  this,  multiplied  by  10,000,  gives  the  niimber 
of  corpu.'^cles  in  a  cubic  millimetre  of  blood.  In  the 
healthy  blood  of  man  the  standard  is  5,000,000  in 
each  cubic  millimetre.  The  depth  of  colour  has  now 
to  be  determined.  To  ascertain  this  two  tubes  have 
*  Lancet,  Dec.  1st,  1877  ;  and  vol.  ii.,  page  822, 1878. 


76  Clinical  Chemistry.  [Chap.  hi. 

to  be  employed ;  the  one  containing  a  solution  o£  a 
standard  tint,  equivalent  to  the  dilution  of  20  cubic 
millemetres  of  blood  in  2  cubic  centimetres  of  water, 
the  other  graduated  so  that  2  cubic  centimetres  give 
100  degrees.  The  tubes  are  placed  side  by  side,  and 
a  sheet  of  white  paper  placed  behind  them.  20  cubic 
millimetres  of  blood  are  then  placed  in  the  graduated 
tube  by  means  of  a  capillary  pipette,  a  few  drops  of 
distilled  water  being  first  placed  in  the  bottom  of  the 
tube.  The  mixture  is  to  be  kept  constantly  agitated 
by  a  stirring  rod.  Distilled  water  is  then  gradually 
added  until  the  tint  of  the  diluted  blood  is  exactly 
the  same  as  that  of  the  standard  solution.  In  healthy 
blood  the  tint  is  reached  at  100  degrees  of  dilution. 
In  blood,  poor  in  hsemogiobin,  the  degree  of  dilution 
required  to  give  the  normal  tint  is  less ;  so  that  60, 
70,  or  80  degrees  of  dilution  only  may  be  required. 
The  result  of  these  two  observations  is  recorded  as 
the  value  of  each  corpuscle.  Thus  the  blood  from  a 
patient  yields  4,000,000  corpuscles  for  the  cubic 
millimetre,  instead  of  the  normal  standard,  5,000,000. 
In  other  words,  the  percentage  of  corpuscles  is  80 
instead  of  100,  and  the  amount  of  dilution  required  to 
bring  the  blood  to  the  standard  tint  is  60  centimetres, 
and  if  we  take  the  percentage  of  corpuscles  as  a 
denominator,  and  the  percentage  of  colour  as  a  nume- 
rator, then  %%  —  \  as  the  vahie  of  a  nominal  cor- 
puscle. The  hsemacytometer  is  also  used  for  deter- 
mining the  proportion  of  white  to  red  corpuscles. 

(6)  Spectrosco'piG  characters  of  hcemoglohin  and  its 
comfounds. — Whenever  a  tube*  containing  undiluted 
blood  is  interposed  between  a  source  of  light  and  a 
spectroscope,  the  whole  of  the  rays,  with  the  exception 
of  the  red,  are  obscured.     On  gradually  diluting  the 

*  Or  more  conveniently  a  liamatinometer,  a  vessel  with  two 
jjarallel  glass  faces,  one  centimetre  apart,  so  that  the  depth  of  the 
stratum  examined  may  be  accurately  determined. 


Chap.  III.I 


SfECTRUM  OF  Blood. 


77 


blood  the  spectrum  cleai-s  up,  and  the  red,  orange,  and 
yellow  become  visible,  and  a  portion  of  the  green 
beyond  e.  But  between  D  and  K  there  is  an  intensely 
dark  space.  On  further  dilution  this  gradually  clears 
up,  leaving  however  two  bands  (Fig.  1,  No.  1),  one  at 
a,  near  to  D,  with  well-detined  edges,  and  whose 
centre  corresponds  to  580 — 578  of  the  wave-line. 
The  other,  h,  broader,  less  shaded  and  defined  at  the 


Wave  line. 
Oxj-ha-moglubin. 

Reducoil  hiBiuOb-lnliin. 


Motliajmnglohin  in  alka- 
line solutions. 


Mctlixraoglobin  in  acid 
soUuious. 


Reducod  lixmatin. 


Hieraitin     in     alkaline 
solutions. 


H^inatin  in    acid   solu- 
tions. 

Fig.  1.— Spectrum  of  Hsemoglobiu  and  its  Compounds. 


edges,  near  to  E,  whose  centre  corres])onds  to  5-40  — 
543  of  the  wave-line.  The  two  bands  are  charac- 
teristic of  oxy-htemoglobin.  The  space  occupied  by 
these  bands  is  a  measure  of  the  amount  of  haemo- 
globin present.  Thus,  in  a  solution  one  centimetre 
thick,  and  containing  0  8  per  cent,  htemoglobin,  the 
two  bands  are  continuous  from  595  to  520,  whilst 
the  green  just  beyond  518  is  slightly  visible;  by 
increasing  the  .strength  of  the  solution  the  green 
disappears.  With  0-35  per  cent,  the  bands  are  sepa- 
rated ;  a  extends  from  588  to  568,  and  b  55-i  to  524. 


7 8  Clinical  Chemistry.  [Chap.  hi. 

With  0"09  per  cent,  solution  a  extends  from  583 — 
571,  and  h  from  550 — 532,  with  less  than  0-01  per 
cent,  a  is  faint  and  extends  between  583  and  575,  h  is 
visible  with  difficulty,  but  Professor  Gamgee  gives  its 
position  as  538 — 550.  If  we  add  certain  reducing 
agents  to  the  blood,  carefully  excluding  aii",  then  the 
oxy-hsemoglobin  is  deprived  of  its  oxygen,  and  we 
have  the  spectrum  of  reduced  hcemoglobin  ;  this  gives 
a  single  broad  band  extending  from  595 — 540,  ditfuse 
at  its  edges,  and  darkest  between  560 — 550  (Fig.  1, 
No.  2).  The  agent  generally  used  for  effecting  the  re- 
duction is  a  solution  of  stannous  chloride,  to  which 
a  small  quantity  of  tartaric  acid  is  added,  and  the 
mixture  neutralised  with  ammonia.  When  a  solution 
of  haemoglobin  is  exposed  for  long  to  the  air,  or  to  the 
action  of  certain  oxydising  agents  (ozone,  potassium 
permanganate,  sodium  nitrite,  amyl  nitrite,  etc.)  in 
neutral  or  faintly  alkaline  solutions,  it  forms  a 
yellowish  -  brown  solution,  and  is  converted  into 
methcemoglobin  (Fig.  1,  Nos.  3  and  4).  The  nature  of 
this  body  is  not  well  understood.  Formerly  it  was 
supposed  to  be  per-oxy-hsemoglobin.  It  does  not, 
however,  form  oxy-hsemoglobin  under  the  action  of 
reducing  agents,  but  passes  directly  into  the  reduced 
haemoglobin.  This  and  other  considerations  have 
made  recent  writers  view  methsemoglobin  as  contain- 
ing less  oxygen  and  more  iron  than  oxy-htemogiobin, 
but  that  the  oxygen  is  in  a  more  stable  condition 
than  in  the  latter  body.  In  nearly  all  solutions 
containing  methsemoglobin,  the  two  bands  of  oxy- 
hsemoglobin  are  generally  visible.  This  is  accounted 
for  by  the  presence  of  a  portion  of  oxy-hsemoglobin 
not  being  transformed  into  methaemoglobin.  The 
fluids  of  certain  cysts,  the  deposits  after  the  extravasa- 
tion of  blood  into  the  cellular  tissue,  the  blood  after 
inhalations  of  nitrous  oxide,  or  the  administration 
of  the  nitrites,  and  the  urine  in  lisematinuria,  give  the 


Chap.  111.1  II^EMOGLOIilS. 


1') 


cliaractpristic  spoctrosoopic  appojiranco  of  motlut'iiio- 
glohin.  When  a  solution  of  ha'niOf,'l()bin  is  treated  with 
acetic  acid,  the  two  bands  between  D  and  e  vani.sh, 
and  instead  we  have  a  broad  band  between  c  and  d, 
whose  centre  coiresponds  to  wave  lengtli  (i'l^,  this  the 
spectrum  of  acid  hcemntin  (Fig.  1,  No.  6).  If  the 
solution  be  now  rendered  strongly  alkaline,  this  band 
shifts  nearei"  D,  with  a  centre  corresponding  to  GIO  of 
the  wave  line,  whilst  the  blue  end  of  the  spectrum 
becomes  more  ob.scure.  This  is  the  spectrum  of 
alkaline  ho'.matin  (Fig.  ],  No.  6).  If  to  either  acid 
an  alkaline  solution,  the  reducing  agent  (stannous 
chloride,  tartaric  acid,  and  ammonia)  be  added,  no 
bands  are  seen  in  c,  D,  but  in.stead  two  bands,  not 
unlike  those  of  oxy-hajmoglobin,  are  seen  between  D 
and  E,  one  a  broad  band  reaching  from  D  half  way  to 
E,  and  the  other  a  narrower  band  near  E ;  this  is  the 
spectrum  of  reduced  hcematin  (Fig.  1,  No.  7).  The 
spectrum  of  acid  hpematin  is  not  unlike  that  of  methiie- 
nioglobin  in  an  acid  solution,  and  lias  been  mistaken 
for  it ;  by  rendering  the  sohition  alkaline  the  resem- 
blance disappears. 

(c)  The  chemical  properties  of  the  colouring  matter 
of  the  blood. — The  detibrinated  blood  of  the  rat, 
squirrel,  or  guinea-pig,  received  into  a  beaker  sur- 
rounded with  ice,  and  allowed  to  stand  a  short  time, 
yields  abundant  and  well-detined  crystals  of  htemo- 
globin,  but  with  the  blood  of  the  ox,  sheep,  horse,  or 
man,  the  separation  in  the  crystalline  form  is  not  so 
readily  obtained,  and  the  following  process  must  be 
followed  : — 100  centimetres  of  freshly  di'awn  blood 
must  be  rajndly  detibrinated  and  placed  in  a  shallow 
vessel  and  treated  with  ten  times  its  volume  of  10  per 
cent,  solution  of  sodium  chloride,  and  set  aside  in  a 
cold  place  (in  summer  ])laced  in  a  refrigerator)  ;  when 
the  corpuscles  are  deposited  the  supernatant  liquid  is 
decanted    off,    and    the    mass    })laced    in  a  filter  and 


8o 


Clinic  A  l  C hem  is  tr  v. 


[Chap.  III. 


washed  repeatedly  with  sodium  chloride  sohition  till 
the  washings  are  completely  free  from  albumin.  It  is 
then  agitated  with  a  mixture  of  one  volume  of  water 
to  four  volumes  of  ether,  and  allowed  to  stand ;  the 
etherial  solution  contaiiiing  the  fatty  matter  is  then 
removed,  and  the  red  aqueous  solution  filtered  into  a 
Leaker  surrounded  with  ice,  and  alcohol  carefully 
added  till  a  precipitate  begins  to  appear.     After  some^ 

hours  crystals  of 
hfemoglobin  will 
form.  The  success 
of  the  proceed- 
ing depends  on 
thoroughly  remov- 
ing the  albumin 
and  fatty  matters, 
and  conducting  the 
whole  process  at  a 
low  temperature. 
The  crystals  in  man 
form  as  prismatic 
needles,  with  dihedral  summits,  or  in  rhombic  plates, 
Fig.  2,  c  and  d.  They  are  soluble  in  water  and  alka- 
line solution,  and  are  insoluble  in  alcohol,  chloroform, 
and  ether.  Acids  decompose  them  with  the  forma- 
tion of  hgematin. 

Ho])pe     Seyler    gives   the    composition   of    dried 
crystallised  haemoglobin  as, 


Fig.  2 — Haemoglobin  Crystals. 
A,  Of  guinea-iiig ;  B,  of  squirrel ;  c,  D,  hiunan. 


c     . 

.  54-01 

H  . 

.   7-20 

N   . 

.  16-17 

Fe  . 

•42 

S   . 

•72 

0   . 

.  21-48 

100-00 


Chsp.  III.) 

HMytOGLOBIN. 

from   which  the  fonnula  CaooHagoN, 

MFeS,( 

adduced  ;  and 

12 

X 

600  C 

= 

7200 

1 

X 

960  H 

= 

960 

14 

X 

l.n  N 

= 

2156 

56 

X 

1  Fe 

= 

56 

32 

X 

3  S 

= 

96 

16 

X 

179  0 

= 

2864 

8i 
may  be 


13332 

gives  the  molecular  weight  13332.  And  as  one 
molecule  of  htenioglobin  requires  three  molecules  of 
soda  to  form  non-coagiilable  combinations,  therefore 
^^^=4444,  or  the  equivalent  weight  of  haemo- 
globin. 

The  amount  of  oxygen  linked  with  hsemoglobin  to 
form  oxy -haemoglobin,  is  1"27  cubic  centimetres  of 
oxygen  at  0'^  C.  and  1  metre  pressure  to  1  gramme  of 
haemoglobin.  Carbonic  oxide  and  nitrous  oxide  dis- 
place the  oxygen  in  oxy -haemoglobin,  the  solution  ac- 
quiring a  bluish  tint,  but  the  spectrum  is  little  altered, 
and  is  not  atiected  by  reducing  agents,  whilst  the 
combination  seems  more  stable  than  that  of  oxygen 
with  hemoglobin.  Hcemafin  C^,H-oNgFe.jO,„  is  best 
prepared  by  mixing  defibrinated  blood  with  a  strong 
solution  of  potassium  carbonate,  till  the  liquid  ad- 
hering to  the  separated  coagulum  becomes  colourless. 
The  coagulum  is  then  dried  at  50'  C.  and  digested  for 
some  days  in  absolute  alcohol ;  the  alcoholic  solution 
after  concentration  will  deposit  rhombic  crystals. 
Haematin  crystals  are  of  a  bluish-black  colour  with  a 
metallic  lustre,  becoming  brown  on  trituration.  They 
are  insoluble  in  water,  alcohol,  ether,  and  chloroform, 
but  soluble  in  acids  and  alkalies ;  the  acid  alcoholic 
solutions  are  monochromatic,  having  a  brown  colour ; 
the  alkaline   solutions  are  dichromatic,  and  have  an 

G 


82  Clinical  Chemistry.  [Chap.  hi. 

olive-green  colour  and  dark  red  in  the  thicker  layers. 
The  crystals  support  a  temperature  of  180°  C,  but 
above  that  they  carbonise.  When  treated  with 
strong  sulphuiic  acid  hsematin  is  deprived  of  its  iron  ; 
this  substance,  to  which  Hoppe  Seyler  has  assigned 
the  name  of  hceynatojjopiyhyrin  (thus,  CggH-oNgOnjFe,  + 
4S0,H,  +  03  =  Ce8H,oN30,o(SO,H,)  +  2reS0,  +  2H,b), 
gives  to  the  spectrum  a  dark  band  midway  between 
D  and  E,  and  a  narrow  band  between  c  and  D 
(nearer  d)  ;  the  spectrum  also  is  deeply  shaded 
between  D  and  e.  If  a  solution  of  haemoglobin 
reduced  by  hydrogen  is  decomposed  by  sulphuric 
acid,  a  substance  is  formed  which  Hoppe  Seyler  has 
named  hcemocromogen,  and  which  by  oxydation  yields 
hsematin.  This  body  when  in  alkaline  solution  is 
identical  with  reduced  haematin,  whilst  in  acid  solution 
its  spectrum  gives  a  combination  of  those  of  acid  hse- 
matin and  hsematopopphyrin. 

Hcemin  G^^ -^^ ^^qJJ ^,,C\,  or  hsematin  hydrochlo- 
ride ;  if  a  small  quantity  of  blood  is  rubbed  iip  with 
sodium   chloride   and  boiled  for  a  few  minutes  with 

^  ^jf     glacial    acetic  acid,  and  the  mixture  evapo- 

•     rated    to    dryness,    in    the    residue,    mixed 

f»  i    with   colourless  crystals  of  sodium  chloride 

and  sodium  acetate,  will  be  found  rhombic 

Hffimin^  tablets  of  hsemin  (Fig.  3)  ;  which  are  of  a 
Crystals,  bluish  -  red  colour  when  viewed  by  re- 
flected, and  brownish  -  red  by  transmitted,  light. 
They  are  insoluble  in  hot  and  cold  water,  in 
alcohol  and  ether.  Soluble  in  alkaline  solutions. 
All  acids,  with  the  exception  of  hydrochloric  and 
acetic  acid,  decompose  them.  Heated  to  200°  C. 
they  undergo  decomposition,  evolving  fumes  of 
prussic  acid,  and  leaving  a  residue  of  oxide  of  iron. 

Hcematoidin  G^^^^^^z  (Robin  and  Verdeil). 
Under  this  name  Yirchow  described  certain  red 
ciystals   found    in  clots  of  old  extravasations,  as  in 


Ch;«p.  III.)  Blood  Stains.  %i 

a])oplectic  clots,  corpora  lutea,  etc.  They  li.ivt;  been 
considered  to  be  identical  with  bilirubin,  but  the 
question  is  not  yet  decided.  They  can  be  obtained 
from  the  corpora  lutea  by  rubbing  them  np  with 
j)ounded  glass,  agitating  frofjuently  with  chloroform. 
After  standing  .some  time  the  chloroform  solution  is 
poured  ofF  and  allowed  to  evaporate.  The  crystals 
thus  obtained  are  red  by  transmitted,  and  green  by 
reflected,  light ;  they  occur  in  rhombic  plates,  and 
•are  soluble  in  chloroform  and  ether,  but  insoluble  in 
alcohol,  water,  and  alkali. 

96.  Exaiiiiiiatioii  of  blood  stains. —  The 
surface  or  substance  of  the  material  mnst  be  scraped 
or  cut  into  small  fragments  and  digested  in  as  little 
distilled  water  as  possible.  Of  the  reddish  fluid 
examine  (1)  under  microscope  for  blood  corpuscles  ; 
(2)  placed  in  deep  narrow  cell  and  examined  by  a 
spectroscopic  eye-piece  with  a  low  power  of  micro- 
scope, for  bands  of  haemoglobin  ;  (3)  add  a  few  dro])s 
of  glacial  acetic  acid  and  a  small  quantity  of  sodium 
chloride  evaporated  to  dryness  at  40°  0.  and  50°  C, 
and  examine  residue  for  haimin  crystals  ;  (4)  place  a 
drachm  of  tincture  of  guiacum  in  a  test  tube  and  add 
a  drop  of  the  solution,  then  float  on  surface  etherial 
solution  of  hydrogen  peroxide;  if  blood,  a  blue  I'ing 
will  form  at  junction  of  the  etherial  solution  and  the 
guiacum.  (N.B. — Other  substances  besides  blood 
give  this  reaction  with  guiacum.) 

97.  The  colourless  corpuscles — These  are 
the  white  and  the  intermediate.  The  former  are  nu- 
cleated masses  of  protoplasm  of  granular  appearance, 
possessing  the  power  of  amreboid  movement.  They 
are  larger  than  the  red  corpuscles,  the  diameter  l)eing 
77..^^jjth  of  an  inch.  The  intermediate  or  hiemato- 
blasts  are  smaller  than  the  white  corpuscles,  and 
the  nucleus  is  more  obscured  by  granules.  Treated 
with  acetic  acid  the  colourless  corpuscles  swell   up, 


84  Clinical  Chemistry.  [Chap.  hi. 

rendering  the  nuclei  more  distinct.  Tonclied  with  a 
solution  of  iodine  and  potassium  iodide,  the  body  of 
the  corpuscles  is  stained  a  mahogany-brown,  indicating 
the  presence  of  glycogen.  The  proportion  of  white 
corpuscles  to  red  may  be  stated  as  1  to  340 — 350, 
but  the  proportion  varies  considerably  under  different 
physiological  conditions,  being  increased  by  fasting 
and  diminished  by  food.  In  leucocythsemia  the  pro- 
portion of  white  corpuscles  to  red  is  greatly  increased, 
so  as  often  to  amount  to  one-eighth  or  one-tenth  of 
the  coloured  corpuscles  ;  they  are  of  the  same  shajae  as 
in  normal  blood,  but  often  smaller.  On  standing, 
delicate  crystals  often  form  in  them ;  these  are  sup- 
posed to  be  a  phosphate  of  a  proteid  base.  In  pro- 
gressive pernicious  anseraia  the  white  corpuscles  are 
not  absolutely  increased.  In  addition  to  the  white 
corpiiscles  in  leucaemia  and  pernicious  ansemia,  there 
are  often  nucleated  coloured  corpuscles  similar  to 
those  found  in  the  blood  of  the  human  embryo ;  in  these 
cases  the  marrow  of  the  bones  is  generally  affected, 
whether  as  a  primary  or  secondary  condition  is  still 
undetermined. 

98.  Blood  serum,  as  it  separates  from 
coagulated  bloodj  is  clear  fluid  of  a  straw  colour,  sp. 
gravity  1'025 — 1"028;  its  alkaline  reaction  is  higher 
than  an  equal  bulk  of  blood.  It  contains,  in  addition 
to  fatty  matters,  extractives,  and  salt,  the  other  pro- 
teids  of  the  blood,  viz.,  paraglobulin  and  serum  albu- 
mirL  Paraglobulin,  serum  globulin,  or  fibrinoplastic 
substance,  is  precipitated  from  blood  serum  by  adding 
to  it  magnesium  sulphate  to  complete  saturation  when 
it  is  precipitated.  Hammarsten  by  this  method  has 
obtained  3 '103  parts  of  paraglobulin  in  100  parts  of 
blood.  It  is  said  to  pass  easily  through  animal  mem- 
branes, which  serum  albumin  does  not.  It  is,  there- 
fore, not  improbable  that  some  cases  of  temporary 
albuminuria  may  be  due  to  the  passage  of  this  body 


ciiap.  III.)      Fatty  Matters  of  Blood.  85 

into  the  urine,  and  not  altogether  to  the  presence  of 
seruin  albumin,  as  generally  Hnp])ose(l.  J*ai-agIobulin 
with  lil)rinogen  in  the  presence  of  the  fil)rin  feiMnent 
forms  fibrin  ;  fibrinogen,  however,  is  only  found  in  the 
blooil  plasma.  The  seruin  albitniin  can  be  obtained 
after  the  removal  of  the  paraglobulin,  by  gently  con- 
centrating the  filtrate  at  a  low  temperature,  30°  C, 
to  35°  C,  and  then  placing  it  on  a  dialyser  to  remove 
saline  impurities ;  the  solution  will  then  give  the  re- 
actions described  (§  20). 

99.  Fatty  inaltei-s.  —  A  definite  quantity  of 
blood  is  evaporated  to  dryness  over  a  water-bath,  and 
when  completely  dry  the  mass  is  bi'oken  up  and 
carefully  triturated  in  a  mortar,  and  the  powder 
thoroughly  exhausted  with  boiling  ether.  The  etherial 
solution  is  then  evaporated  in  a  weighed  ])latinum 
capsule.  The  increased  weight  of  the  capsule  gives 
the  amount  of  fats  in  the  quantity  of  blood  examined. 
Normal  blood  yields  from  -18  to  -2  per  cent,  of  fatty 
matter,  which  consists  of  saponitiable  fats,  lecithin, 
and  cholesterin,  the  tvvo  latter  being  chiefly,  if  not 
altogether,  derived  from  the  corpuscles.  To  obtain  these 
bodies  separately,  the  residue  in  the  platinum  capsule 
must  be  again  treated  with  ether  and  boiled  with 
baryta  water  ;  the  fatty  acids  are  thus  converted  into 
baryta  soap,  and  can  be  removed  by  filtration.  The 
precipitate  is  then  treated  with  absolute  ether,  which 
removes  the  cholesterin  from  the  soaps,  and  is  evapo- 
rated on  a  weighed  filter  and  the  amount  of  cholesterin 
ascertained.  The  filtrate  is  then  divided  into  two  por- 
tions. One  is  evaporated  till  it  is  dry,  and  is  then 
extracted  with  absolute  alcohol ;  the  neurin,  one  of  the 
products  of  the  decomposition  of  lecithin,  is  then  pie- 
cipitated  by  platino-chloride  solution,  as  neurin  platino- 
chloride.  The  other  portion  of  the  filtrate  is  evaporated 
to  dryness,  and  fused  with  sodium  hydrate  and  nitre, 
and  the  residue  dissolved  in  water  and  nitric  acid  added 


86  Clinical  Chemistry.  [Chap.  in. 

in  excess  ;  a  solution  of  ammonium  molybdate  gives 
a  yellow  deposit,  which  is  to  be  dissolved  in  ammonia. 
To  this,  solution  of  magnesium  sulphate  and  ammo- 
nium chloride  is  added,  and  on  spontaneous  evapora- 
tion crystals  of  ammonio- magnesium  phosphate  will 
form.  The  ciystals  are  collected  in  a  platinum  capsule, 
and  ignited  as  directed  for  the  determination  of  mag- 
nesia (§  85).  Then  since  100  parts  of  the  pyrophosphate 
are  equivalent  to  764"8  parts  of  lecithin,  a  calculation 
of  the  amount  of  lecithin  present  can  be  made.  Thus 
if  the  weight  of  the  pyrophosphate  amounts  to  "026 
grammes,  then  the  lecithin  will  amount  to  0 "19764 
grammes,  but  as  only  half  the  filtrate  was  taken,  then 
the  total  lecithin  in  the  fatty  residue  will  be  0-39528, 
Now  supposing  the  amount  of  blood  examined  for 
fatty  matter  yielded  a  residue  of  total  fats  of  1'9  per 
cent. ,  then  by  deducting  the  weight  of  the  cholesterin, 
which  on  weighing  has  been  found  to  be  -08  grammes, 
and  deducting  the  weight  of  the  lecithin  as  found  above, 
we  have  the  weight  of  the  saponifiable  fat.  So  that 
100  grammes  of  blood  have  yielded  1'9  parts  of  mixed 
fats,  of  which  '08  is  cholesterin,  -395  is  lecithin,  and 
the  remainder  1'425  saponifiable  fat.  The  amount  of 
fat  in  the  blood  is  increased  after  a  full  meal  and 
diminished  during  fasting.  In  diabetes  the  blood 
sometimes  assumes  a  lactescent  appearance  {lijoceinia), 
due  to  the  presence  of  excess  of  fatty  matter.  This 
condition,  which  is  rare,  is  generally  met  with  in  cases 
that  have  run  an  acute  course,  and  terminate  in  a 
peculiar  form  of  coma.  (/S'ee  Acetonsemia.)  Cholesterin, 
it  is  said,  is  also  to  be  found  in  excess  in  the  blood  in 
cases  of  liver  disease.     {See  Cholestersemia. ) 

100.  ExtB'actives  consist  chiefly  of  urea,  glu- 
cose, kreatin,  hypoxanthine,  and  uric  acid.  (1)  Urea 
can  be  determined  either  (a)  by  diluting  50  grms.  of 
blood  with  200  of  distilled  water  and  adding  five  drops 
of  sulphuric   acid,  and  boiling  the  mixture.     Filter. 


cii.ip.  III.)  ExrnACTivES  in  Blood.  87 

To  tlie  (iltr;it(!  .'kM  a  saturated  solution  of  luiiyla 
liyili'iito  (2  voluiiH's)  aiiil  l)ariuin  iiitrati!  (I  voluiiu;)  io 
throw  down  sulpliates  and  })lioKjiliatc.s,  and  add  a 
few  drops  of  strong  solution  of  silver  nitrate 
to  precijjitate  chlorid(!S.  Filter.  Add  cautiously  to 
iiltrate  some  sulj)liuric  acid  till  there  is  an  acid 
reaction.  Filter.  Evai)orate  filtrate  to  consistence  of 
syrup,  and  add  50  cc.  of  absolute  alcoliol.  Filter. 
Evaporate  alcoholic  solution  and  dissolve  residue  in 
50  cc.  of  water.  To  this  add  cautiously  from  a  Mohr's 
burette,  drop  by  drop,  Liebig's  solution  of  mercuric 
niti'ato  (see  Urine, §  110),  diluted  with  an  equal  quantity 
of  distilled  water,  stirring  after  each  addition,  and 
removing  a  drop  of  the  mixture  to  a  plaster  of  Paris 
slab  moistened  with  drops  of  sodic  carbonate  solu- 
tion. When  a  yellow  stain  is  given  to  one  of  these 
droi)s,  no  more  mercuric  solution  is  to  be  added.  As 
1  cc.  of  tlie  mercuric  solution  is  equivalent  to 
•005  gramme  of  urea,  the  number  of  centimetres  of 
the  solution  used  indicates  the  amount  of  urea  in 
50  cc.  of  blood,  {b)  Detibrinate*  20  cc.  of  blood, 
place  it  on  a  parchment  jaaper  dialyser,  and  spread  it 
over  it  so  as  to  foiin  a  thin  layer.  Float  it  in  a 
vessel  containing  50  cc.  of  absolute  alcohol.  From 
time  to  time  add  a  very  little  distilled  water  to  keep 
the  mass  on  dialyser  moist ;  continue  the  process  for 
twelve  hours.  Treat  the  diffusate  with  an  equal 
bulk  of  solution  of  concentrated  oxalic  acid,  and 
evaporate  to  dryness.  To  residue  add  some  naphtha 
petroleum  to  i*emove  fatty  matters.  Dissolve  the 
purified  residue  in  a  little  water,  and  add  barium  car- 
bonate. Eva|)orate.  Treat  tlie  residue  with  boiling 
alcohol  and  filter.  Concentrate  filtrate,  from  winch 
on  cooling  urea  will  crystallise  out.  The  pei'centage 
amount  of  urea  in  healthy  blood  ranges  from  '025  to 
•035  grras.  In  Bright's  disease,  acute  yellow  atrophy 
*  Uayci'aft's  method,  from  Professor  Gamgce's  work. 


88  Clinical  Chemistry.  [Chap.  iii. 

of  the  liver,  and  in  gout,  the  amount  is  considerably- 
increased. 

(2)  Glucose.  Dr.  Pavy's  process  gives  the  most 
reliable  results  hitherto  obtained.  It  is  as  follows  :— 
Forty  grammes  of  sulphate  of  soda  in  small 
crystals  are  weighed  out  in  a  beaker  of  about  200  cc. 
capacity.  About  20  cc.  of  the  blood  intended  for 
analysis  is  then  poured  upon  the  crystals,  and  the 
beaker  and  its  contents  again  carefully  weighed.  The 
blood  and  crystals  are  well  stirred  together  with  a 
glass  rod,  and  about  30  cc.  of  a  hot  concentrated  solu- 
tion of  sulphate  of  soda  added.  The  beaker  is  placed 
over  a  flame  guarded  with  wire  gauze,  and  the  contents 
heated  until  a  thoroughly  formed  coagulum  is  seen  to 
be  suspended  in  a  clear  colourless  liquid ;  to  attain 
which  actual  boiling  for  a  short  time  is  required.  The 
liquid  has  now  to  be  separated  from  the  coagulum,  and 
the  latter  washed  to  remove  all  the  sugar.  This  is 
done  by  first  pouring  off  the  liquid  through  a  piece  of 
muslin  resting  in  a  funnel  into  another  beaker  of 
rather  larger  capacity.  Some  of  the  hot  concentrated 
solution  of  sulphate  of  soda  is  then  poured  on  the 
coagulum,  well  stirred  up  with  it,  and  the  whole 
thrown  on  the  piece  of  muslin.  By  squeezing,  the 
liquid  is  expressed;  and  to  secure  that  no  sugar  is  left 
behind,  the  coagulum  is  returned  to  the  beaker, 
and  the  process  of  washing  and  squeezing  repeated. 
The  liquid  thus  obtained  may  be  fairly  regarded 
as  containing  all  the  sugar  that  existed  in  the  blood. 
From  the  coarse  kind  of  filtration  and  squeezing 
employed,  it  is  slightly  turbid,  and  requires  to  be 
thoroughly  boiled  to  prepare  it  for  filtration  through 
ordinary  filter-paper.  A  perfectly  clear  liquid  runs 
through,  and  to  complete  this  part  of  the  operation 
the  beaker  that  has  been  used,  and  the  filter-paper,  are 
washed  with  some  of  the  concentrated  solution  of 
sulphate  of  soda  before  referred  to. 


Chap.  III.)  Sugar  in  Blood.  89 

The  next  step  is  boiling  with  tlie  copper-test  solu- 
tion.  The  liquid  is  aguiu  placed  over  a  flame,  and 
broufjfht  to  a  state  of  ebullition.  A  suiHcient  quantity 
of  the  cojjper  solution  to  leave  some  in  excess  is  now 
poured  in,  and,  from  the  time  of  i-ecommencement  of 
boiling,  brisk  ebullition  is  allowed  to  continue  for  a 
period  of  one  minute.  As  regards  the  amount  of 
copper  solution  to  be  used,  although  10  cc.  of  the 
test,  as  ordinarily  made,  are  found  to  suttice  for  20  cc. 
of  the  blood  of  animals  in  a  natural  state,  yet  it  is 
well  to  employ  from  20  to  30  cc.  to  secure  that  it  is 
thoroughly  in  excess.  Where,  from  any  circum- 
stance, larger  quantities  of  sugar  exist  in  the  blood, 
more  in  proportion  of  the  test  must,  of  course,  be  used. 

The  precipitated  suboxide  of  copper  has  now  to 
be  separated  fi'om  the  excess  of  copper  solution. 
Experience  shows  that  filti-ation  through  tilter-paper 
cannot  be  resorted  to  for  the  purpose.  A  material, 
however,  which  has  somewhat  recently  been  intro- 
duced, viz.,  glass-wool,  fully  furnishes  what  is  wanted. 
Properly  packed  in  the  neck  of  a  funnel,  it  permits 
filtration  to  be  efiectively  and  easily  performed.  The 
filtrate  should  always  be  carefully  examined,  to  see  if 
the  plug  has  been  sufficiently  tightly  packed  to  keep 
the  whole  of  the  precipitate  back.  Should  the 
crystallisation  of  the  sulphate  of  soda  in  this  or  the 
preceding  tiltration  interfere  with  the  continuance  of 
the  operation,  the  funnel  may  be  placed  over  a  beaker 
holding  some  liquor  kept  in  a  state  of  ebullition,  or 
heat  may  be  applied  in  any  other  way. 

The  suboxide  having  been  collected,  and  washing 
with  distilled  water  performed,  it  is  retui-ned  to  the 
beaker  in  which  the  reduction  was  etFected,  to  secure 
that  none  of  the  precipitate  that  may  have  been 
adhering  to  the  sides  of  the  vessel  is  lost.  The  plug 
is  pushed  with  a  glass  I'od  from  the  neck  of  the 
funnel  held  in  an  inverted  position  over  the  beaker, 


90  Clinical  Chemistry.  [Chap.  iii. 

and  the  funnel  washed  and  its  surface  cleaned  from 
all  adhering  precipitate.  Now  the  suboxide  is  in  a 
fit  state  to  dissolve,  and,  after  the  addition  of  a  few 
drops  of  peroxide  of  hydrogen,  a  very  small  quantity 
of  nitric  acid  (a  few  drops  only)  is  sufficient  to  lead 
to  instantaneous  solution,  and,  after  boiling,  to  decom- 
pose the  excess  of  peroxide  of  hydrogen,  the  contents 
of  the  beaker,  consisting  of  filter-plug  and  dissolved 
precipitate,  are  poured  into  a  funnel  containing  a 
loose  plug  of  glass-wool,  to  obtain  the  liquid  in  a 
separate  form.  The  requisite  washing  with  distilled 
water  having  been  performed,  there  only  remains  the 
final  stage  of  the  process  to  be  accomplished. 

The  liquid  to  be  now  dealt  with  contains  the 
copper  in  the  form  of  nitrate,  which  experiment  has 
shown  to  be  the  most  suitable  for  yielding  a  pure 
metallic  deposit  by  galvanic  action.  For  the  purpose 
of  collecting  the  deposit,  a  cylinder  of  platinum  foil, 
soldered  to  a  platinum  wire  for  hooking  on  to  the 
negative  pole  of  the  battery,  is  employed.  This  is 
immersed  in  the  liquid  so  as  nearly  to  touch  the 
bottom  of  the  vessel,  and  inserted  within  it  is  a  spiral 
coil  of  platinum  wire,  made  to  constitute  the  positive 
pole  of  the  battery.  In  order  to  secure  a  good  con- 
tinuous connection,  the  platinum  spiral  is  closely 
bound  to  the  copper  conducting- wire  of  the  battery, 
and  the  other  pole  is  provided  with  a  platinum  hook 
for  the  suspension  of  the  cylinder.  At  the  end  of 
twenty-four  hours'  exposure  to  galvanic  action  the 
weight  of  the  cylinder  with  the  deposited  coj)per  is 
taken.  The  cylinder  is  lifted  quickly  out  of  the 
liquid,  and  instantly  plunged,  first  into  distilled 
water,  and  then  into  spirit,  the  latter  being  used  to 
avoid  the  occurrence  of  oxydation  of  the  copper  in 
drying.  After  drying  by  suspension  in  a  water- 
oven,  the  process  of  weighing  is  performed,  and  it  is 
hardly   necessary    to    say   that   a    delicate    chemical 


Chap.  m.|  See  Ah'  IN  Blood.  91 

lialance  is  required  for  tlie  purpose.  The  weight  of 
the  cylinder  boini^  known  and  subtracted  gives  the 
woiglit  of  the  copper  that  lias  been  thrown  down.  Jn 
the  case  of  an  analysis  of  blood  containing  an 
ordinary  amount  of  sugar,  and  therefore  yielding  a 
liniiteil  amount  of  copper  to  be  deposited,  twenty- 
four  hours  have  usually  been  found  to  suffice  for  the 
completion  of  the  oi)eration  ;  but  it  is  necessary  there 
should  be  no  uncertainty  upon  this  point,  and,  to 
secure  this,  the  following  course  of  procedure  should 
be  adopted.  After  the  weighing  has  been  etlected, 
the  deposited  copi)er  is  dissolved  ofl'  by  immersion  of 
the  cylinder  in  nitric  acid,  and  the  cylinder  then 
returned  into  the  liquid  to  see  if  any  fresh  deposit 
occurs.  If,  after  some  hours,  no  copper  tint  is  seen, 
the  operation  may  be  regarded  as  completed ;  but,  if 
more  deposit  has  occurred,  the  immersion  must  be 
continued,  and  another  -weighing  performed,  and  this 
repeated  till  the  platinum  sui-face  remains  untinted. 

The  galvanic  action  requii'es  to  be  steadily  and 
continuously  maintained,  and  a  modification  of  Fullei's 
mercury-bichromate  battery  has  been  found  to  answer 
best  for  use.  The  arrangement  that  was  employed 
in  Dr.  Pavy's  experiments  consisted  of  an  outer  cell 
provided  with  two  carbon  plates,  and  charged  with  bi- 
chromate of  potash  dissolved  to  saturation  in  dilute  sul- 
phuric acid.  Into  the  inner  porous  cell  a  little  mercury 
is  poured,  and  it  is  then  filled  up  with  water.  An 
amalgamated  zinc  rod  is  inserted,  and  dips  down  into 
the  layer  of  mercury  at  the  bottom.  This  battei'y,  it 
is  found,  gives  a  steady  current,  and,  used  every  day, 
will  remain  in  good  working  order  for  at  least  a 
fortnight,  all  that  is  necessary  being  to  poiir  out  the 
liquid  in  the  porous  cell  when  it  has  become  green 
from  reduction  of  the  ditiused  biehi'omate  solution, 
and  replace  it  with  water.  Attention  is,  of  course, 
necessary  to    secure    that   the    proper   battery -power 


92  Clinical   Chemistry.  [Chap.  in. 

exists  to  effect  the  deposition  of  the  copper,  and,  when 
the  current  becomes  weak,  the  zinc  rod  must  be  cleaned, 
and  the  bichromate  of  potash  solution  replenished. 

When  sugar  is  boiled  with  the  copper  solution, 
the  change  occurring  stands  in  the  relation  of  one 
atom  of  the  foi'mer  to  five  atoms  of  cupric  oxide. 
One  atom  of  sugar  is  oxydised  by,  or  reduces,  five 
atoms  of  cupric  oxide.  This  is  the  foundation  of  the 
action  involved  in  the  operation  of  the  test,  and  the 
calculation  of  the  amount  of  sugar  present  is  made 
accordingly.  Taking  634  as  the  atomic  weight  of 
copper,  and  180  as  that  of  glucose  CgHijOg,  317 
parts  of  copper  will  stand  equivalent  to  180  parts  of 
glucose.  Thus,  one  part  of  copper  corresponds  to  '5678 
of  glucose,  and,  in  calculating  the  amoimt  of  sugar  in 
the  blood  analysed,  the  weight  of  the  copper  deposited 
has  only  to  be  multiplied  by  '5678  to  give  its 
equivalent  in  glucose.  The  quantity  of  sugar  in  the 
amount  of  blood  taken  for  analysis  being  thus  deter- 
mined, the  required  information  is  supplied  for 
expressing  the  proportion  for  1000  parts. 

(3)  Kreatin  is  found  in  only  very  small  quantities 
in  blood.  In  order,  therefore,  to  obtain  it  in  any 
appreciable  amount,  large  quantities  of  blood  are 
required  for  analysis.  Take  1000  grms.  of  blood, 
and  remove  albuminous  constituents,  phosphates,  sul- 
phates, and  chlorides,  as  described  for  the  determina- 
tion of  urea.  The  clear  filtrate  is  then  precipitated 
by  a  solution  of  basic  lead  acetate.  Filter.  The 
filtrate  is  then  decomposed  by  sulphuretted  hydrogen 
to  remove  the  lead,  and  filtered  through  animal 
charcoal.  The  filtrate  is  then  evaporated  gently  to  a 
syrupy  consistence,  and  treated  with  twice  its  volume 
with  alcohol,  from  which  mixture  crystals  of  kreatin 
(§  62)  will  deposit.  [The  student  who  wishes  to 
obtain  kreatin  as  a  specimen  can  readily  obtain  it 
by  dissolving  5  grms.   of   meat  extract  in   50  cubic 


ciiap.  1 1  I.I  Salts  of  Blood.  93 

centimetres  of  water,  adding  basic  lead  acetate,  and 
proceeding  with  the  filtrate  as  directed  above.] 

(4)  Ilypoxanthin  is  found  in  the  juice  of  flesh,  in 
the  s[)loon,  and  in  the  thymus  and  thyroid  glands.  Jn 
loucocytluvmia  it  is  found  in  appreciable  quantities  in 
the  blood.  To  determine  it,  take  100  grms.  of  blood, 
and  separate  the  albuminous  constituent,  the  phosphate 
sulphate,  and  chlorides.  The  aqueous  solution  is 
then  treated  with  ammoniacal  solution  of  silver 
nitrate,  as  directed.     (.See  Urine,  §  125.) 

(5)  Uric  acid  cannot  be  obtained  from  healthy 
lilood  in  quantities  suflicient  for  identification.  In 
gout,  however,  this  suljstance  can  be  obtained  for 
examination  by  placing  about  two  drachms  of  serum 
(ol)tained  from  a  blister)  in  a  large  watch-glass,  and 
adding  to  it,  by  means  of  a  glass  rod,  acetic  acid 
till  it  has  a  decided  acid  reaction.  Place  in  the  mix- 
ture a  fibre  of  coarse  linen,  and  allow  it  to  stand  till 
the  contents  of  the  watch-glass  become  gelatinous  ; 
then  take  out  the  fibre,  and  crystals  of  uric  acid  will 
be  found  adhering  to  it  (§  111 ). 

101.  Salts. —  The  inorganic  residue  of  blood  is 
generally  determined  by  incinerating  a  gi\'en  quantity 
of  blood  in  a  muffle  furnace,  or  over  a  Bunsen  lamp,  till 
tlie  ash  is  nearly  colourless,  and  making  a  quantitative 
estimation  of  the  acids  and  bases  present.  This 
method  is  sufficiently  accurate  when  we  wish  to  deter- 
mine only  the  bases  ;  but,  in  the  case  of  the  phosphates 
and  sulphates,  it  is  liable  to  error,  since  the  phos- 
phorus contained  in  the  phosphorised  fats,  and  the 
suljihur  from  the  proteids,  become  oxydised^  and  com- 
bines with  the  bases.  It  is  therefore  best  to  calculate 
the  bases  directly  from  the  ash,  according  to  directions 
§§  8.5  and  88,  and  make  a  separate  detei'mination  of 
the  acids  directly  from  the  blood.  This  can  be  done 
by  placing  a  small  quantity  of  blood,  dried  at  a  low 
temperature    and    completely    pulverised,    and    then 


94  Clinical  Chemistry.  [Cnap.  in. 

moistened  with  water,  on  a  clialysei%  and  floatinof  it  in 
a  small  quantity  of  distilled  water,  till  what  comes 
froin  the  dialyser  when  placed  in  a  fresh  quantity  of 
distilled  water  no  longer  gives  a  haze  with  solution  of 
silver  nitrate.  The  diffusate  contains  both  the 
oxydised  and  unoxydised  inorganic  residue,  and  the 
former  can  be  calculated  volumetrically  by  the  pro- 
cesses given  for  the  estimation  of  phosphoric  acid 
(§  113),  hydrochloric  acid  (§  114),  and  sulphuric  acid 
(§  115).  [See  Urine.)  An  analysis  so  conducted 
yielded  the  following  results  :  100  parts  of  blood  the 
ash  yielded,  lime,  "Oil  ;  magnesia,  -006  ;  potash,  -034  ; 
soda,  "374;  iron  oxide,  -045;  phosphoric  acid,  -112; 
sulphuric  acid,  "035 ;  hydrochloric  acid,  -285.  This 
analysis  shows  the  preponderance  of  soda  over  potash, 
a  preponderance  which  is  still  more  marked  if  only 
the  serum  be  taken  for  analysis.  On  the  other  hand, 
the  potassium  salts  are  more  abundant  in  the  cor- 
puscles (§  10).  The  chlorides,  again,  are  more  abun- 
dant in  the  serum,  the  phosphates  in  the  corpuscles. 
"With  regard  to  the  combination  existing  between  the 
bases  and  the  acids,  the  soda  combines  with  chlorine 
to  form  0-53  per  cent,  of  the  ash,  and  with  phos- 
phoric acid  as  neutral  phosphate  Na2HP04,  whilst 
•15  2^arts  of  soda  are  combined  with  carbonic  acid  as 
normal  carbonate  NajHCOs,  and  as  acid  carbonate 
NaHaCOg.  It  is  owing  to  the  decomposition  re- 
sulting between  the  neutral  phosphate  of  soda  and  the 
acid  carbonate  that  acid  secretions  are  separated  from 
the  alkaline  blood  (§  9),  a  fact  I  showed  experi- 
mentally in  1874,*  and  which  has  subsequently  been 
confirmed  by  other  observers.  The  phosphoric  acid 
is  chiefly  combined  with  potash  in  the  corpuscles,  and 
with  lime  and  soda  in  the  serum. 

102.  Toxic  conditions  of  the  Mood.— When 
any  impediment  is   offered  to  the   excretion   of   the 
*  Lancet,  July,  1874. 


Chap.  III.  1  AsriiYXiA.  95 

effete  materials  of  Ww.  organism  by  the  natural  chan- 
nels, thnsc  accumulate  in  the  blood,  and  induce  symp- 
toms of  great  gravity.  When,  for  instance,  the  process 
of  aeration  of  the  blood  by  means  of  the  lungs  is 
checked  to  any  great  extent,  carV)onic  acid  accumulates 
in  the  lihiod.and  the  condition  of  nspltyxia  is  induced. 
This,  when  the  blockage  of  the  air-jKissages  is  com- 
plete, proves  rapidly  fatal.  In  less  severe  forms  of 
obstruction,  the  condition  is  marked  by  dyspncea,  and 
a  more  or  less  livid  and  purplish  condition  (n/rniosis) 
of  the  skin  and  visible  nnicous  membranes,  due  to  the 
presence  of  imperfectly  aerated  blood  in  the  capillaries. 
Cyanosis  is  the  most  conspicuous  symptom  of  con- 
genital deformity  of  the  heart.  Insufficiency  of  the 
tricuspid  valve,  causing  as  it  does  great  engorgement 
of  the  veins  of  the  systemic  circulation,  is  generally 
accompanied  by  marked  cyanosis.  In  emphysema, 
especially  in  the  later  stages,  when  the  right  side  of 
the  heart  ceases  to  compensate  by  its  hypertrophy  for 
the  circulatory  impediment,  the  cyanosis  becomes  ex- 
tremely intense ;  even  in  the  early  stages,  with  the 
loss  of  the  interalveolar  septa  and  disappearance  of  the 
capillaries,  the  imperfect  aei'ation  of  the  blood  is 
manifest  in  the  leaden  hue  of  the  patient's  countenance. 
In  disease  affecting  the  left  side  of  the  heart,  cyanosis 
is  not  a  marked  symptom.  Niemeyer  ingeniously  ac- 
counts for  this  by  the  su])position  that  in  valvular  affec- 
tions of  the  left  heart  the  pulmonary  circulation  is  sur- 
charged with  blood,  whilst  the  quantity  of  blood  in 
the  systemic  circulation  is  abnormally  small  ;  whilst 
in  emphysema,  whei'e  many  pulmonary  capillaries  have 
perished,  and  in  diseases  of  the  tricuspid  and  pul- 
monary valves,  it  is  the  systemic  circulation  which  is 
o\'erloaded,  whilst  the  pulmonary  contains  too  little 
blood  for  effectual  aeration.  In  diseases  accompanied 
by  diminution  in  the  number  and  colour  v.due  of  the 
red   corpuscles,   in    addition    to   the    pallor,   there   is 


96  Clinical  Chemistry.  [Chap.  in. 

usually  a  well-marked  leaden  hue ;  this  is  particularly 
noticeable  in  patients  suffering  from  scurvy. 

In  diseases  of  the  kidney,  when  the  excretion  of  the 
solid  matters  of  the  urine  is  considerably  diminished, 
a  condition  known  as  urcsinia  often  supervenes.  This 
is  generally  attended  by  a  drowsy  condition,  more  or 
less  intense,  with  the  frequent  recurrence  of  convul- 
sions of  an  epileptic  character.  The  urine  is  greatly 
diminished ;  but  if  it  should  be  increased,  as  it  is  in 
some  rare  cases,  it  is  of  very  low  specific  gravity. 
Numerous  views  have  been  advanced  to  account  for 
the  symptom.  Some  consider  it  due  to  the  poisonous 
action  per  se  of  retained  urea ;  others,  that  the  urea 
is  decomposed  into  ammonium  carbonate,  and  the 
blood  is  poisoned  with  ammonia ;  while  others  hold 
that  excess  of  urea  in  the  blood  causes  the  water  of 
that  fluid  more  readily  to  transude  through  the  capil- 
laries, and  thus  cause  oedema  of  the  brain.  Against 
these  views  it  maybe  urged  that  urea  may  be  injected 
in  large  quantities  into  the  veins  of  animals  without 
inducing  ursemia;  that  no  ammoniacal  odour  is  percep- 
tible in  the  health  of  persons  suffering  from  this 
condition,  whilst  in  typhus  fever,  in  which  ammonia 
has  been  recognised  in  the  breath  by  many  reliable 
observers,  the  coma  is  not  of  urjemic  character.  And 
lastly,  ureemic  convulsions  occur  in  some  cases  without 
there  being  evidence  of  any  marked  diminution  in  the 
excretion  of  urea,  as  in  puerperal  convulsions.  In 
this  condition  a  considerable  quantity  of  albumin  is 
passed  in  to  the  urine,  amounting,  in  three  examina- 
tions I  have  made,  from  six  to  eleven  grms.  in  the 
twenty-four  hours ;  the  urea,  on  the  other  hand,  was 
only  slightly  below  the  normal  rate  of  excretion.  Con- 
sidering ureemic  convulsions  occur  chiefly  in  cases 
where  the  drain  of  albumiai  has  been  considerable, 
either  in  large  quantities  as  in  acute  nephritis,  or  in 
small  quantities  but  of  long  continuance,  as  in  chronic 


Chap.  III.]  Ur.-emia.  97 

renal  disease,  I  tliink  we  may  reasonably  attribute 
the  condition  in  some  measure  to  the  withdrawal  of 
the  nutritive  matter  of  tlie  blood,  or,  at  least,  to  the 
altered  percentage  relationship  between  it  and  the 
effete  (extractive)  materials.  One  point  is  clear,  that 
venesection  often  proves  of  immense  service  in  this 
condition,  -  apparently  by  altering  the  percentage 
comi)osition.  In  one  case  of  uraemic  convulsions, 
in  a  lady  seven  months  advanced  in  pregnancy,  Avhose 
urine  I  examined  at  the  request  of  Dr.  John  Williams, 
I  found  in  the  urine  passed  during  twelve  hours 
immediately  preceding  Aenesection,  5"1  grammes  of 
albumin,  whilst  the  urine  passed  in  the  twelve  hours 
immediately  after  venesection  only  contained  2-3 
grammes.  Free  purgation,  by  relieving  the  tension 
in  the  renal  capillaries,  has  much  the  same  etlect, 
though  to  a  less  extent.  A  patient  in  a  state  of 
deep  coma,  which  had  been  preceded  by  convul- 
sions, had  a  drop  of  croton  oil  administered,  his 
urine  at  the  time  containing  about  one-fifth  albu- 
min ;  after  free  purgation  he  recovered  conscious- 
ness for  several  hours  and  the  urine  was  found  on 
examination  to  contain  only  one-twelfth  albumin. 

In  diseases  of  the  liver,  when  any  obstruction  is 
offered  to  the  onward  passage  of  the  bile,  re-absorption 
takes  place,  and  the  bile  passes  into  the  blood  and  is 
deposited  in  the  tissues,  giving  rise  to  the  phenomenon 
of  jaundice.   (See  Bile,  chapter  v.) 

In  certain  forms  of  liver  disease,  particulai'ly 
cirrhosis,  in  which  there  is  a  great  destruction  of 
liver  cells,  the  termination  is  by  coma,  and  has  been 
attributed  to  the  retention  of  cholesterin  in  the 
blood  {cholesteriemia) .  We  have  no  evidence,  how- 
ever, to  show  that  cholesterin  has  any  toxic  influ- 
ence. Krusenstern  injected  from  'OOo  to  '045  gramme 
of  cholesterin  daily  into  the  veins  of  dogs,  and  found 
the  animals  unafl'ected.       Pag^s  arrived  at  the  samj 

H    . 


98  Clinical  Chemistry.  [Chap.  iii. 

results.  *  Looking  at  the  question  from  the  purely  clini- 
cal side,  one  would  expect  cholestersemia  in  all  cases  of 
jaundice  where  there  was  considerable  resorption  of 
bile.  If  the  liver  is  the  seat,  as  is  generally  held,  of 
the  destruction  of  the  blood  corpuscles,  which  contain 
nearly  all  the  cholesterin  found  in  the  blood  in.  the 
normal  state,  we  may  naturally  suppose  the  cholesterin 
of  the  bile  re-absorbed  in  a  free  state  into  the  blood, 
would  rapidly  induce  cholestersemia;  but,  as  a  matter  of 
fact,  the  phenomena  attendant  of  this  condition  are 
not  common  to  jaundice,  due  simply  to  obstructions, 
however  complete,  unless  there  be  also  considerable 
destruction  of  liver  tissue  and  disease  of  the  kidneys. 
Again,  in  acute  yellow  atrophy,  where  we  have  rapid 
destruction  of  the  liver  cells,  and  where  jaundice  is  com- 
paratively slight,  the  coma  is  preceded  and  attended 
with  symptoms  much  resembling  those  witnessed  wlien 
acids,  or  phosphorus,  are  injected  into  the  veins  of 
animals,  or  in  patients  dying  from  acute  diabetic  coma 
(acetonsemia).  From  these  considerations  I  venture  to 
think  that  the  coma  attendant  upon  hepatic  disease  in 
which  there  is  considerable  destruction  of  liver  cells,  is 
not  due  to  the  accumulation  of  cholesterin,  which,  in 
many  cases  of  ordinary  jaundice,  increases  four  or  five 
per  cent.  (Frerichs)  without  inducing  the  condition,  but 
to  a  general  increase  of  the  excretory  matters  in  the 
blood,  and  this  supposition  is  strengthened  by  the  fact 
that  the  condition  is  never  witnessed  iinless  there  is 
also  some  impairment  as  well  of  the  renal  functions. 

In  diabetic  urine  there  is  often  found  a  body  that 
gives  with  ferric  chloride  a  deep  red  reaction,  and  cor- 
responds, in  many  respects,  with  acetone,  or  acetone- 
yielding  bodies.  As  this  substance  has  been  found 
most  frequentlyt  in  the  urine  of  patients  dying  rapidly 

*  Journal  de  VAnatomie  et  de  la  Physiologie,  1875. 
t  Acetone  can  be  obtained  from  most  diabetic  urines  by  dis- 
tillation with  hydrochloric  acid. 


Chap.   III.)  ACETON^EI^IIA.  99 

of  acute  clial)etic  coma,  it  has  been  supposed  that  this 
phenomena  is  due  to  the  presence  of  acetone  in  the 
blood  (acetoncemia).  Fi-ee  acetone,  however,  has  not, 
I  believe,  ever  been  obtained  in  a  free  state  from 
fioshly-drawn  diabetic  blood,  but  there  is  little  doubt 
that  a  body  readily  yielding  acetone  can  be  separated 
from  the  blood  of  such  patients.  The  nature  of  this 
body  is  a  matter  of  some  dispute ;  most  writers  consider 
it  to  be  ethyl  diacetate,  Avhich,  by  decomposition, 
yields  equal  molecules  of  acetone  and  alcohol.  In  this 
case,  by  distillation  we  ought  to  obtain  equal  amounts 
of  acetone  and  alrohol ;  indeed,  as  acetone  is  the  most 
volatile,  it  should  be  found  in  less  amount.  Some 
recent  observations,*  however,  have  shown,  on  the  con- 
trary, that  when  diabetic  uj-ine  is  distilled,  the  acetone 
is  considerably  in  excess  of  the  alcohol,  and  hence  it 
has  been  surmised  that  the  body  is  some  compound  of 
aceto-acetic  acid.  When  acetone,  or  the  acetone- 
yielding  body,  is  found  in  the  urine,  there  is  as  Avell  a 
])eculiar  odour,  like  that  of  acetone,  exhaled  by  the 
breath,  and  the  urine  likewise.  This  odour  is  gene- 
rally particularly  noticed  as  preceding  acute  diabetic 
coma,  though  when  that  condition  is  thoroughly  esta- 
blished, it  often  disappears.  After  death,  a  lactes- 
cent or  milky  appearance  is  sometimes  noted,  with 
fatty  changes  of  the  liver  and  otlier  viscera,  though 
these  conditions  are  far  from  being  invariable.  Acute 
diabetic  coma  or  acetontemia  is  distinguished  from 
the  more  common  but  less  characteristic  form  of  coma, 
which  usually  tei-minates  the  disease,  in  the  sudden- 
ness of  its  onset,  the  gastric  disturbance,  as  shown  by 
the  acute  epigastric  pain,  the  vomiting  (sometimes  of 
blood),  and  more  rarely,  frequent  purging  ;  the  pecu- 
liar noisy  delirium,  the  panting  respiration  like  an 
animal  with  both   vagi  cut,   the   fluctuations  in  the 

*  Deicbmuller,  Annalen,  209,  22—30.    B.  Tollens,  Annalen,  209, 
30—38. 


loo  Clinical  Chemistry,  [Chap.  hi. 

rapidity  of  the  pulse,  which  maintain  till  the  coma  is 
well  established,  when  the  pulse  continues  intensely 
rapid  and  small.  These  are  symptoms  which  come 
on  in  rapid  succession,  and  present  a  parallel  to 
those  which  occur  in  acute  yellow  atrophy  and  phos- 
phorus poisoning,  or  the  injection  of  the  bile  acids 
or  mineral  acids  into  the  blood  of  animals.  The  origin 
of  the  acetone-yielding  body  has  not  been  determined, 
but  it  is  probable  that  it  is  derived  from  some  meta- 
morphosis of  the  sugar  in  the  blood,  forming  alcohol 
and  the  products  of  alcoholic  fermentation.  When 
we  consider  the  highly  acid  character  of  the  urine  in 
diabetes,  and  the  fact  that  symptoms  of  acute  diabetic 
coma  are  not  unlike  those  produced  in  animals 
poisoned  by  the  injection  of  acid  into  their  veins,  it  is 
not  improbable  that  the  body  concerned  is  of  an  acid 
nature — aceto-acetic  acid,  as  has  been  suggested.  This 
body  is  probably  present  in  the  blood  of  most  diabetics, 
in  small  quantities,  and  by  its  elimination  from  the 
urine  gives  that  secretion  the  highly  acid  reaction  met 
with  in  diabetes.  When,  however,  it  is  formed  in 
excessive  quantities,  or  its  elimination  is  interfered 
Avith,  it  accumulates  in  the  blood,  giving  )-ise  to  the 
condition  known  as  acetonsemia.  The  presence  of 
acetone,  or  the  acetone-yielding  body,  can  be  demon- 
strated in  urine  by  the  deep  red  coloration  given  by 
ferric  chloride,  which  disappears  on  the  addition  of 
hydrochloric  acid,  and  by  the  reaction  with  iodide  of 
potassium.  This  last  I  have  endeavoured  to  make 
available  as  a  clinical  test,  as  follows  ;  About  a  drachm 
of  liquor  potassoe,  containing  twenty  grains  of  iodide  of 
potassium,  is  placed  in  a  test  tube  and  boiled ;  a 
drachm  of  the  suspected  urine  is  then  carefully  floated 
on  the  surface.  Where  the  urine  comes  in  contact 
with  the  hot  alkaline  solution,  a  ring  of  phosphates  is 
formed,  and  after  a  few  minutes,  if  acetone  or  its  allies 
are  \)resent,  the  ring  will  become  yellow,  and  studded 


cii.ip.  iii.i  CiiVLi-:  AND  T.VMrir.  loi 

\\'\\\\  j-fUow  points  of  ioiloffiiiii  ;  (licsc  in  (iiiio  will  sink 
thi-oii^rh  (lio  liiiLf  of  plioK])liiit('S,  jiikI  iieconio  dei)ositc(| 
at  tlio  hottom  of  the  test  tube. 

10;5.  Chyle  siekI  lyinB»li. —  In  examining  tlicsf; 
fluids  the  same  steps  arc  to  be  taken  as  in  the  examina- 
tion of  blood,  and  the  same  methods  cm[)loyed  for  the 
determination  of  (ho  specific  gravity,  the  reaction,  the 
amount  of  librin  and  other  proteids,  the  fatty  mattei", 
the  extractives,  and  the  salts.  The  chyle  derived  frcjm 
the  intestinal  lacteals  does  not  contain  fibrin,  and 
consequently  does  not  separate  into  clot  and  serum. 
If  the  animal  has  l)een  fasting,  the  chyle  loses  its  creamy 
appearance  and  becomes  more  transparent  and  of  a 
yellowish  colour.  100  pai-ts  of  chyle  yield,  when 
taken  from  the  lacteals  in  full  digestion  :  water,  91'8  ; 
solids,  8 "2;  librin,  0-2;  proteids,  3 '5;  fats,  3-3;  extrac- 
tives, 0'4;  salts,  0'8;  when  fasting:  water,  9G'8;  solids, 
•38;  fibrin,  -09;  proteids,  2'30;  fat,  "04;  extractives, 
•28;  salts,  •49.  The  proteids  consist  of  serum  albumin, 
paraglobulin,  fibrinogen,  and  peptones.  The  fatty 
matters,  which  consist  of  minute  spherical  globules, 
and  form  what  Gulliver  called  the  molecular  base  of 
the  chyle,  are  a  mixture  of  saponifiable  fats,  cliolcs- 
terin,  and  lecithin  (100  parts  of  ether  extract  yield 
81^  saponifiable  fat;  7^5  parts  lecithin;  11'3  parts 
cholesterin  ;  Hoppe  Seyler).  The  extractives  are  urea, 
and  glucose,  whilst  leucin  and  tyrosin  are  frequently 
obtained.  The  constitution  of  the  ash  resembles  that 
of  the  blood,  the  sodium  having  a  prepondei-ance  over 
the  potassium  salts.  Lympli  is  a  clear,  colourless,  or 
straw-coloured  fluid,  of  sliglitly  alkaline  reaction.  In 
composition  lymph  closely  resembles  chyle,  differing 
chiefl}'-  in  the  smaller  proportion  of  fibrin  and  fatty 
matters  it  contains. 

104.  Milli. — The  following  gives  the  average 
composition  of  human  milk  in  100  parts:  water,  86^86; 
solids,  13-2;  proteids  (chiefly  casein)  2-93,  butter  3'78, 


I02  .  Clinical  Chemistry.  [Chap.  hi. 

sugar  of  milk  5 '83,  extractives  0'25,  salts  0"35. 
It  varies,  however,  considerably  with  the  character  of 
the  food  and  other  physiological  conditions.  Of  the 
constituents,  however,  the  casein  and  sugar  are  the 
most  constant,  whilst  the  fatty  matters  show  a  wide 
range  of  variability.  Analyses  have  shown  that  the 
composition  of  milk  varies  with  the  age  of  the  infant. 
Thus  the  casein  is  at  its  lowest  at  the  commencement 
of  suckling,  and  then  gradually  rises  till  it  attains  a 
fixed  proportion,  whilst  the  sugar  is  at  its  maximum 
at  the  commencement  and  subsequently  diminishes. 
This  is  important  in  relation  to  the  artificial  feeding 
of  infants.  A  comparison  of  human  milk  with  cows' 
milk  shows  that  the  latter  contains  more  casein  but  less 
sugar,  whilst  asses'  milk,  though  poorer  in  casein  than 
human  milk,  is  quite  as  rich  in  sugar.  The  colostruvi 
or  the  milk,  passed  during  the  first  week  after  delivery, 
has  a  more  alkaline  reaction  and  higher  specific 
gravity  than  ordinary  milk,  and  is  richer  in  casein  and 
fatty  matters.  In  certain  morbid  conditions  the 
composition  of  the  milk  may  be  altered,  though 
observations  on  this  point  are  much  wanting.  In 
pyrexia  the  secretion  is  diminished,  or  may  be  quite 
suppressed,  and  the  quantity  of  solids,  chiefly  the  fats 
and  sugar,  fall  considerably.  After  undue  excitement, 
shock,  mental  emotion,  the  milk  has  been  noticed  to 
have  an  acid  reaction,  or  to  become  so  shortly  after 
secretion.  In  some  cases  rapid  decomposition  sets  in 
with  the  evolution  of  sulphuretted  hydrogen.  Certain 
substances  taken  as  food  or  medicine  find  their  way  into 
the  mammary  secretion  and  for  a  time  render  it  unfit 
for  use.  During  the  latter  stage  of  pregnancy  and  the 
earlier  period  of  lactation  sugar  sometimes  appears  in 
the  urine;  this  must  not  be  confounded  with  the  grape 
sugar  of  true  diabetes,  but  is  the  milk  sugar,  lactose 
(F.  Hofmeister  "Ueber  Lactosurie,  Zeitsch.  f.  Phys. 
Chem."    i.    §    101),    and  can  be  distinguished  by  its 


ciiap.  IV.)  Milk.  103 

pliysical  iind  chemical  characters  (§  13).  Milk  some- 
times assumes  a  distinctly  Mue  ajJiK-araiice;  this  is  duo 
to  the  development  of  bacteria.  When  milk  is  added 
to  an  artilicial  solution  of  gastiic  juice  it  becomes 
curdled,  and  this  curd  is  gradually  dissolved  as  diges- 
tion proceeds.  This  curdling  is  not  due  to  the  acid  of 
the  gastric  juice,  but  to  some  ferment  which  sets 
up  lactic  acid  fermentation  in  the  milk  sugar,  as 
is  evident  by  the  fact  that  if  the  artificial  juice  is 
neutralised  before  the  addition  of  the  milk,  the 
curdling  takes  place  just  the  same.  The  specific 
gravity  of  the  milk  and  its  alkaline  reaction  are 
determined  by  the  same  methods  as  described  for 
blood.  The  casein  is  separated  by  adding  a  few  drops 
of  acetic  acid,  and  boiling.  Collecting  the  curd  and 
drying  it,  rubbing  up  the  dried  residue  in  a  glass 
mortar  and  frequently  extracting  with  ether  to  remove 
the  fatty  matter  ;  placing  the  purified  residue  on  a 
weighed  filter  and  drying  it.  The  fatty  matter, 
extractives,  and  salts  are  determined  as  directed  for 
blood.  The  lactose  can  be  obtained  as  directed  by 
Pavy's  method  for  separating  glucose  from  blood,  or 
can  be  estimated  directly  by  Fehling's  process  (see 
Urine),  after  the  milk  has  been  freed  from  albumin. 


CHAPTER   IV. 

MORBID    CONDITION'S    OF    URINE. 

105.  Examination   of  morbid   urine. —  In 

order  to  draw  conclusive  results  fi'om  the  examination 
of  urine  in  disease,  a  systematic  plan  of  procedure  must 
be  adopted  and  the  circumstances  and  conditions 
under  which  the  secretion  was  passed  precisely  stated. 


T04  Clinical  Chemistry.  [Char.  iv. 

The  neglect  of  ttese  precautions  i-enders  many  investi- 
gations valueless,  whilst  in  some  instances  it  leads  to 
erroneous  conclusions  being  drawn.  As  is  well  known, 
the  specific  gravity,  the  reaction,  and  proportionate 
relationship  of  the  different  constituents  of  the  urine, 
even  in  health,  vary  considerably  during  different 
periods  of  the  day,  whilst  in  disease  such  variations 
are  still  more  considerable.  It  is  evident,  therefore, 
if  v/e  wish  to  arrive  at  a  right  conclusion  as  to  the 
nature  of  the  pathological  condition  with  which  we 
have  to  deal,  our  observations  must  be  based  upon  an 
examination  of  the  Avhole  of  the  urine  passed  during  a 
period  of  twenty-four  hours.  If  that  is  not  always 
possible,  from  at  least  two  samples ;  the  one  taken  on 
first  rising  in  the  morning,  the  other  two  hours  after 
the  principal  meal  of  the  day.  No  definite  conclusion 
sliould  eve'^  be  drawn  from  the  exaviination  of  a  single 
sam,ple  of  tirine  jjassed  within  tioenty  hours.  In  noting 
the  character  and  qualities  of  urine  in  disease  the 
following  scheme  may  advantageously  be  followed : 
(1)  State  the  circumstances  under  which  the  urine 
was  passed ;  whether  it  represents  the  secretion  of  the 
twenty-four  hours,  or  is  only  a  specimen  passed  at 
some  period  diiring  the  day;  if  the  latter,  state  the 
time  when  voided.  (2)  Record  the  quantity  presented 
for  examination  (if  the  twenty-four  hours'  urine  has 
been  collected,  give  the  amount),  the  sjDecific  gravity 
and  reaction,  note  also  its  colour  and  odour  and 
degree  of  clearness.  (3)  Test  for  abnormal  products, 
sugar,  albumin,  etc.  (4)  Collect  deposit  for  chemical 
and  microscopic  examination.  This  procedure  will 
give  us  an  insight  into  the  qualitative  changes  that 
occur  from  day  to  day  in  the  character  of  urine  during 
the  progress  of  disease.  To  determine  the  quantitative 
changes  in  the  amount  of  the  urinary  constituents  two 
methods  are  employed  :  (1)  Exact  chemical  determina- 
tion, which  consists  either  in  precipitating,  collecting, 


Chnp.   IV.l 


Srr.ciFic  Gr a  vi t j '. 


^05 


and  then  weighing  the  precipitated  substance  (the 
"gravimetric  metliod");  or  by  precipitating  or  other- 
wise altering  the  substa,nce  by  means  of  a  solution 
of  a  reagent  of  known  strength,  or  ascertaining  tlie 
quantity  of  the  reagent  required  to  efl'ect  a  complete 
change;  this  is  tlie  "volumetric  method."  (2)  ylpproxi- 
mnte  estimntioih  by  some  ready  means  and  easily 
applied  clinical  motliod,  such  as  calculating  the  amount 
of  urinary  solids  from  the  spocitic  gravity,  or  the 
quantity  of  sugar  by  the  loss  of  weight  occasioned  by 
fermentation  with  yeast,  or  by  the  degree  of  intensity  of 
colour  wiien  compared  with  a  standard  of  comparison. 
Approximate  estimation,  however  useful,  should  never 
be  entirely  relied  on.  Exact  chemical  determinations 
should  always  be  made  from  time  to  time.  In  all 
cases  the  calculation  should  be  made  from  the  urine 
passed  in  a  period  of  twenty-four  hours ;  in  this  way 
we  get  the  absolute  as  well  as  the  relative  amount  of 
the  substances  passing  out  of  the  body  during  this 
period. 

106.  Tariatioti  in  the  urinary  water  and 
solids. —  Specific  |!:i'avity. — The  following  table 
gives  apjiroximately  the  amount  of  the  chief  consti- 
tuents of  the  twenty-four  hours'  urine,  in  a  child,  a 
irrowinir  lad,  and  an  adult. 


JIeax  Amoint  Chief  CoxsTiTrEXTs  of  Normal  HuMAxIJRryE 
PASSED   IX   Twenty-four   Hours. 


5  years 

12  vpars 

35  years 

weight  37J  lbs. 

weight  64i  lbs. 

weight  14-7  lbs. 

Water      . 

450  cc. 

860  cc. 

1,4')0  CO. 

Urea 

11-1  gniis. 

16-7  grms. 

33-4  grms. 

Uric  acid 

0-4      „ 

0-6     •„ 

0-8      „ 

Alkaline  phosphates 

0-9      „ 

1-6      „ 

2-1      „ 

Earthy  phospliates  . 

0-.5      ,. 

0-8      „ 

1-3      „ 

Chlorides 

1-2      „ 

3-4      „ 

6-2      „ 

Sulphates 

0-7      „ 

1-i      ., 

2-6      „ 

io6  Clinical  Chemistry.  [Chap.  iv, 

In  calculating  the  amount  of  solids  passed  in 
disease,  we  must  allow  a  range  of  one-fourth  of  the 
mean  amount,  above  and  below  that  amount.  The 
quantity  of  urine  passed  in  the  twenty-four  hours  is, 
however,  no  measure  of  the  amount  of  solid  matter 
passing  out  of  the  body  by  the  kidneys,  since  30 
ounces  of  urine  may  contain  as  much  solid  matter  as 
60  ounces.  The  amount  of  solid  matter  is  therefore 
determined  either  by  evapoi^ating  the  urine  and 
weighing  the  residue,  or  else  by  taking  the  specific 
gravity  of  the  urine  by  means  of  a  urinometer, 
and  calculating  the  solids  from  the  density.  The 
former  process  is  tedious,  and  requires  an  expen- 
diture of  time  which  precludes  its  employment 
when  examinations  have  to  be  made  daily.  For 
clinical  purposes  the  solids  may  be  calculated,  when 
precautions  are  taken  to  ensure  accuracy,  from  the 
specific  gravity.  The  calculation  is  based  on  the 
fact  that  normal  human  urine  of  twenty-four  hours 
contains  4  per  cent,  of  solid  matter,  and  that  the 
specific  gravity  of  that  urine  is  registered  at  about 
1'020.  By  multiplying  the  two  last  figures  of  the 
specific  gravity  by  2  we  get  40  in  every  1.000  parts, 
or  exactly  4  per  cent.  A  thousand  grains,  therefore, 
of  urine,  specific  gravity  1  "020,  contains  40  grains  of 
solid  matter ;  or,  if  French  measures  are  employed, 
1000  cubic  centimetres  of  the  same  specific  gravity 
contain  40  grammes.  As  stated  in  the  above  table,  the 
quantity  of  water  passed  in  twenty-four  hours  is  1450 
centimetres,  or  50  ounces ;  then  the  quantity  of 
solids  as  calculated  from  the  specific  gravity  discharged 
in  the  same  period  will  amount  to  2  ounces,  or  54 
grms.  In  making  calculations  based  on  the  specific 
gravity,  it  is  important  to  note  the  temperature  at 
the  time  the  observation  is  made,  since  a  difier- 
ence  of  7°  F.  from  the  temperature  at  which  the 
urinometer  was  graduated  represents  a  difierence  of 


Chap.  IV.]  Srr.ciFic  Gravitv.  107 

one  degree.  The  observation  of  tlic  si)ecific  gravity 
in  connection  with  the  amount  of  urine  piissed  in 
the  twenty-four  hours,  aflbrds  in  itself  an  important 
indication  as  to  tlic  metamorphoses  going  on  in  the 
body. 

Under  the  terms  liydruria,  diabetes,  polyuria,  etc., 
authors  have  described  certain  morbid  conditions  of 
the  urine,  characterised  by  excessive  and  persistent 
discharge.  JNIost  authors  apply  either  of  the  above 
terms  indifferently,  without  reference  to  the  quantita- 
tive relationshij)  that  may  exist  between  the  urinary 
water  a,nd  solids.  The  following  classification  will 
assist  the  memory  : 

(1)  Hijdruria. — A  copious  discharge  of  aqueous 
urine.  In  these  cases  there  may  be  a  decrease  in  the 
solid  constituents  of  the  urine,  but  there  is  certainly 
no  increase.  Extreme  instances  of  liydruria  are  met 
within  cases  of  "diabetes  insipidus,"  in  which  the 
daily  urinary  flow  may  amount  to  7,000  to  9,000 
cubic  centimetres  of  a  specific  gravity  of  1  '002.  As  a 
temporary  condition  it  is  frequently  met  with  in 
hysterical  females  and  persons  of  highly  neurotic 
temperament.  Associated  with  minute  traces  of 
albumin,  it  is  a  condition  of  urine  met  with  in 
granular  kidney  ;  the  amount  of  diuresis,  however, 
is  not  so  extreme,  nor  is  the  specific  gravity  so  low,  as 
in  typical  instances  of  diabetes  insipidus. 

(2)  Polyuria. — An  increase  of  water  with  an  in- 
crease of  urinary  solids,  dependent  on  increased  tissue 
metabolism.  In  these  cases  all  the  urinary  con- 
stituents seem  to  be  increased.  In  this  division 
we  have  those  cases  of  increased  elimination  of  urea 
to  which  Prout  assigned  the  term  "  azoturia  " ;  and 
those  cases  which  Dr.  Tessier  has  described  as 
"  phosphatic  diabetes,"  where  the  amount  of  j^jhos- 
phoric  acid  excreted  is  enormously  increased.  "  Azo- 
turia "  and  "phosphatic  diabetes"   are  probably  allied 


io8  Clinic  AT.  Chemistry.  [Chap.  iv. 

conditions,  due  to  increased  tissue  metabolism  taking 
place  under  nervous  disturbance.  Both  forms  have 
been  met  with  associated  with  the  following  con- 
ditions :  (a)  Cases  in  which  nervous  symptoms 
are  predominant;  (6)  accompanying  pulmonary  con- 
sumption ;  (c)  cases  which  alternate  or  co-exist 
with  saccharine  diabetes ;  (rf)  which  run  a  distinct 
course,  resembling  saccharine  diabetes,  but  withoiit 
sugar. 

(3)  Diabetes  mellitus. — Increase  of  the  urinary 
water,  together  with  constant  (unless  checked  by  diet) 
excretion  of  glucose  in  excessive  amounts.  The 
occasional  appearance  of  sugar  in  urine  is  not  to  be 
taken  as  an  indication  of  true  diabetes  mellitus,  but  as 
diie  to  temporary  functional  disturbance  of  the  liver, 
though  it  must  not  be  overlooked  that  temporary 
"glucosuria"  is  often  precursory  of  the  more  serious 
disease.  In  cases  of  diabetes  mellitus  the  relation- 
ship between  the  amount  of  urine  excreted  and  the 
urinary  solids  are  very  various.  In  typical  cases  the 
relationship  is  pretty  constant ;  whilst  the  water 
is  considerably  increased  there  is  superabundance  of 
sugar,  and  the  urea,  probably  owing  to  increase  of 
nitrogenous  diet,  is  considerably  in  excess.  In  a 
second  class  of  cases  we  find  a  considerable  increase 
in  the  amount  of  urine,  the  sugar  moderate  in  quan- 
tity, the  urea  not  much  increased,  in  some  cases 
even  below  the  normal,  and  the  urine  frequently 
albuminous.  In  a  third  group  of  case^s  the  urinary 
water  is  only  moderately  increased,  the  sugar  rarely 
exceeding  2|-  per  cent.,  whilst  the  urea  is  generally 
considerably  in  excess,  more  than  can  be  accounted 
for  by  increase  of  nitrogen  ingested.  No  satisfactory 
explanation  has  been  offered  to  account  for  these 
variations,  the  latter,  as  the  least  frequently  observed, 
is  probably  an  early  stage  of  the  former ;  the  marked 
increase   of  the  urea    excreted,   as  compared    to  the 


Chap.  IV.]  Reaction  of  Urine.  109 

iiioilorate  amount  of  sugar  generally  noticeable,  points 
to  increased  tissue  metabolism.  These  cases,  after  a 
comparatively  mild  course,  often  suddenly  develop 
into  acute  diabetes,  and  run  a  ra[)id  course,  ending  in 
diabetic  coma. 

Baruria. — The  urinary  water  is  not  increased,  may 
even  be  diminished,  but  the  ui'inary  solids  are  in  excess. 
From  the  concentrated  iirine,  urates  are  frequently 
deposited.  Dr.  Fuller  was  the  finst  to  apply  the  term 
baruria  ()3api'/s^  heavy)  to  this  class  of  urines,  which  he 
associated  with  certain  forms  of  dyspepsia  (J/ef/.-6'/ttV. 
Trails.,  vol.  li.).  It  is  a  condition  of  urine  found  in 
a  class  of  cases  described  by  Murchison  as  due  to 
IWictimia. 

Anazotarin. — This  term  was  originally  applied  by 
Willis  to  a  class  of  cases  in  which  there  was  a  copious 
discharge  of  pallid  urine,  with  marked  deficiency  of 
urea.  These  cases,  however,  should  be  referred,  T 
think,  to  the  class  hydruria.  The  term  anazoturia  is 
better  applied  to  the  cases  described  by  Dr.  Andrew 
C'larke  as  due  to  "  renal  inadecpiacy."  In  these  there 
is  no  marked  increase  in  the  amount  of  urine  passed, 
but  a  notable  deficiency  in  the  amount  of  urea 
excreted.  As  it  is  still  uncertain  whether  this  con- 
dition dei)ends  on  inadequacy  of  the  renal  functions, 
or  on  deficient  metamorphosis  of  tissue  generally  ;  a 
term  Avhich  defines  the  actual  condition  of  the  urine, 
rather  than  one  which  commits  us  to  an  hypothesis,  is 
for  the  present  decidedly  the  safest. 

107.  Reaction. — Within  a  period  of  twenty- 
four  hours  the  reaction  of  healthy  urine  will  be  found 
to  vary  considerably.  Thus  before  meals  it  will  have 
a  high  range  of  acidity,  whilst  after  food  it  will  become 
nearly  neutral,  or  even  sometimes  alkaline.  This 
depi'e.ssion  of  acidity,  which  has  been  called  the  alka- 
line tide,  has  been  accounted  for  by  Dr.  Bence  Jones, 
by  the  fact  that   at  the   moment   of    its    occurrence, 


no  Clinical  Chemistry.  [Chap.  iv. 

acid  is  being  drawn  from  the  circulation  to  supplj'- 
the  gastric  juice.  Dr.  Roberts,  of  Manchester,  how- 
ever, regards  the  depression  as  due  to  the  intro- 
duction of  newly-digested  food  into  the  blood,  which 
supplies  it  with  alkaline  bases.  Although  both  ex- 
planations are  based  upon  actual  observation,  yet  as 
the  acidity  of  the  urine  can  be  depressed,  and  even 
rendered  alkaline,  by  other  circumstances  besides  those 
attendant  on  digestion,  as  the  mere  act  of  rising  in  the 
morning  before  breakfast  is  taken,  or  the  cold  douche, 
or  sweating  in  the  vapour  bath,  some  other  explanation 
must  be  offered  to  explain  the  depression  in  these 
cases.  And  this,  I  think,*  is  to  be  found  in  the  fact 
that  there  is  another  channel  by  which  acid  is  with- 
drawn from  the  blood  beside  the  gastric  secretion,  and 
that  is  by  the  lungs.  In  the  explanations  hitherto 
advanced  to  account  for  the  phenomenon  of  the 
alkaline  tide  in  the  urine,  this  fact  has  not  received 
attention.  Dr.  Edward  Smith,  in  his  researches  "On 
the  Elimination  of  Carbonic  Acid,"  has  shown  con- 
clusively that  the  exhalation  of  carbonic  acid  by  the 
lungs  is  increased  by  food  and  diminished  by  fasting, 
and  that  the  amount  exhaled  during  sleep  is  consider- 
ably less  than  is  set  free  in  the  waking  state.  It 
therefore  happens  that  the  time  when  most  carbonic 
acid  is  being  exhaled  corresponds  with  the  time  when 
observers  have  noticed  a  decided  diminution  in  the 
acidity  of  the  urine,  whilst  the  circumstances  that 
diminish  the  exhalation  of  carbonic  acid  (namely^ 
sleep  and  fasting),  are  attended  by  a  rise  in  the  acidity 
of  the  urinary  secretion. 

The  acid  reaction  of  the  urine  is  chiefly,  if  not 
entirely,  due  to  the  presence  of  acid  sodium  phos- 
phate, and  occasionally  to  an  excess  of  acid  salts  of 
hippuric  and  uric  acids.     It  is  only  recently  that  an 

*  "  Morbid  Conditions  of  Urine  dependent  on  Derangements  of 
Digestion."     Chiu-chill,  1882. 


Chap,  iv.i  Reaction  of  Urine.  hi 

explanation  has  been  offered  to  account  for  the 
seeming  paradox  of  the  separation  of  an  acid  secretion 
like  urine  from  alkaline  blood.  In  1874  I  pointed 
out*  that  it  might  V)c  tlie  result  of  the  decomposition 
between  the  neutial  sodium  phosphate  and  acid  sodium 
carbonate  (bicarbonate),  both  of  which  exist  in  the 
blood,  resulting  in  the  formation  of  acid  sodium 
phosphate,  and  noi-mal  sodium  carbonate.  The  former 
diffuses  out  through  the  renal  parenchyma,  whilst  the 
latter  remains  in  the  blood  (§  93).  Maly,  how- 
ever, believes  that  acid  sodium  ])hosphate  exists  in  a 
free  state  in  the  blood,  ami  ho  has  shown  that  if  a 
mixture  of  neutral  sodium  phosphate  and  acid  sodium 
]iliosphate  be  placed  together  in  a  dialyser,  the  acid 
salt  passes  into  the  sui-rouuding  distilled  water. 
Maly's  explanation  has  the  merit  of  simplicity,  but 
it  does  not  wholly  account  for  many  of  the  phenomena 
connected  with  the  variations  in  the  reaction  of  the 
urine.  If,  on  the  other  hand,  the  view  that  the  acidity 
of  the  urine  is  caused  by  the  reaction  between  acid 
sodium  carbonate  and  neutral  sodium  phosphate  be 
accepted,  it  will  explain  another  pai'adox  which  has 
been  observed  by  Bence  Jones,  Beneke,  Parkes,  and 
myself,  to  occur  after  the  administration  of  the 
bicarbonates  (acid  carbonates)  of  ammonia,  potash,  and 
soda,  under  certain  conditions,  viz.  causing  of  an  in- 
creased acidity  of  the  urine.  The  free  acidity  of  the 
urine  is  reckoned  as  oxalic  acid,  and  in  the  healthy 
state  the  total  acidity  of  the  twenty-four  hours'  urine 
is  equal  to  a  degree  of  acidity  rei)resented  by  fi'om  1  -5 
gi-ms.  to  2  grms.  of  oxalic  acid. 

After  it  has  been  passed,  the  urine,  if  originally 
acid,  increases  its  degree  of  acidity  owing  to  the 
acid  fermentation  of  the  pigment  and  extractive 
matters  ;  the  highest  degree  of  this  acid  fermentation 
is  reached  about  the  third  day.  The  urine  then 
*  Lancet,  July  21,  1874. 


112  Clinical  Chemistry.  [Chap.  iv. 

gradually  becomes  alkaline  from  the  ureal  decompo- 
sition. 

In  disease  the  acidity  of  the  urine  may  become 
persistently  highly  acid  or  persistently  alkaline  (fixed 
or  volatile),  or  there  may  be  fluctuations,  a  high  degree 
of  acidity  alternating  with  a  neutral  or  alkaline  con- 
dition. The  variations  in  the  reaction  of  the  urine 
in  disease  will  therefore  be  considered  under  three 
heads. 

(1)  Highly  acid  urine. — Urine  may  become  more 
acid,  relatively,  owing  to  concentration  of  the  urine. 
Thus,  in  hot  weather,  owing  to  the  increased  action  of 
the  skin,  the  amount  of  urinary  water  is  lessened  and 
the  urine  becomes  denser.  Similarly  in  pyrexia, 
especially  if  attended  with  profuse  sweating,  as  in 
rheumatic  fever  and  in  diarrhoea.  In  diabetes  mellitus 
the  acidity  of  the  urine  is  considerably  increased ; 
when  freshly  passed  it  has  a  degree  of  acidity  con- 
siderably above  the  average,  and  becomes  more  acid 
after  being  kept  some  hours,  owing  to  lactic  and  acetic 
acid  fermentation  which  takes  place.  In  acid  dyspepsia, 
so  called  on  account  of  its  supposed  association  with 
hypersecretion  of  acid  gastric  juice,  the  urine  is  at 
times  highly  acid,  alternately,  however,  with  urine 
that  is  neutral  or  even  alkaline.  This  variability  in 
the  reaction  of  the  urine  is  frequently  to  be  met  with 
in  children,  in  whom  irregular  secretion  of  the  gastric 
juice  is  very  readily  excited.  The  degree  of  acidity 
is  determined  by  neutralising  100  cc.  of  urine  with 
a  solution  of  sodium  hydrate,  standardised  so  that 
1  cc.  =  "01  grm.  of  oxalic  acid.  The  number  of  cc.'s  of 
the  standard  solution  employed  to  effect  neutralisation, 
multiplied  by  -Ol  gives  the  degree  of  acidity  in  100  cc. 
of  urine,  and  from  this  the  total  acidity  of  the  twenty- 
four  hours'  urine  can  be  calculated. 

(2)  Urine  alkaline  from  fixed  alkali  — This  con- 
dition is  due  either  to  excess  of  the  alkaline  carbonates 


Chap.  IV.]  Reaction  of  Urine.  1 1 3 

of  soda  and  potash,  or  the  alkaline  j)hosphates;  often  to 
an  excess  of  both,  (a)  Excess  of  alkaline  carbonates  : 
The  urine  eflervesces  on  the  adilition  of  strong  acids  ; 
it  is  generally  turbid  from  precipitation  of  the  earthy 
phosphates,  though  these  are  not  necessarily  excreted 
in  excess.  Indeed,  in  many  cases  I  have  found  them 
diminished  ;  on  the  other  hand,  the  urine  may  contain 
an  excess  of  uric  acid.  This  condition  of  urine  may 
arise,  (1)  from  genernl  debility  and  the  feebleness  witli 
which  the  respiriitory  act  is  performed,  leading  to  the 
accumulation  of  carbonic  acid  in  the  system.  With 
regard  to  this  point,  it  is  interesting  to  note  that 
urine  alkaline,  from  the  presence  of  carbonates  of 
the  fixed  alkalies,  is  frequently  met  with  in  patients 
convalescing  from  acute  diseases.  (2)  Diminished 
secretion  of  bile,  which  is  the  frecjuent  result  of  the 
duodenal  catarrh  produced  by  the  irritation  of  the  acid 
contents  of  the  stomach  being  poui-ed  intothe  intestines, 
gives  rise  to  an  accumulation  of  alkaline  carbonates  in 
the  blood,  the  l)ile  being  the  chief  secretion  by  whicli 
alkaline  salts  are  removed  from  the  body  ;  for  though 
a  portion  of  them  are  undoubtedly  reabsorbed  into  the 
blood  from  the  intestines,  a  considerable  proportion 
of  them  are  discharged  with  the  faeces.  Obstruction, 
therefore,  to  the  discharge  of  bile  leads  to  their  retention 
in  the  blood,  and  consequently  being  eliminated  in 
greater  quantity  by  the  kidney.  (3)  The  acids  formed 
by  fermentative  changes  being  of  the  fatty  acid  series, 
these,  on  entering  the  sj^stem,  are  oxydised  into  carbonic 
acid,  and  this  uniting  with  the  bases  of  the  alkaline 
oxides,  forms  carbonates  of  these  bodies,  and  by  increas- 
ing the  alkalescence  of  the  blood  will  diminish  the 
natural  acidity  of  the  urine  and  even  render  it  alkaline. 
The  dyspepsia  generally  associated  with  this  foi'm  of 
alkaline  urine  is  attended  with  great  depression  of 
spirits,  the  bowels  are  constipated,  flatulence  is  a  pro- 
minent symptom,  the  skin  is  sallow  and  dry,  and  the 
I 


114  Clinical  Chemistry.  [Chap.  iv. 

fiinctions  of  tlie  liver  evidently  deranged.  The  urine, 
after  remaining  alkaline  for  some  days,  depositing 
oxalates  and  phosphates,  often  becomes  suddenly  acid, 
and  deposits  large  quantities  of  uric  acid. 

(6)  Excess  of  alkaline  phosphates  of  soda  and 
potash  :  Little  is  known  regarding  the  pathological 
significance  of  ui'ine  alkaline  from  this  cause.  It  is, 
however,  frequently  met  with  in  neurotic  individuals. 
In  the  majority  of  cases  the  earthy  phosphates  are  in- 
creased as  well  as  the  alkaline  carbonates.  Excessive 
elimination  of  the  alkaline  phosphates  has  been  noticed 
in  cases  of  acute  inflammation  of  the  membranes  of 
the  brain,  in  the  acute  paroxysms  of  certain  forms  of 
mania,  after  injuries  to  the  head,  and  in  certain  obscure 
spinal  afiections,  probably  functional  in  character. 
The  urine,  in  these  cases,  is  generally  increased  in 
quantity  ;  on  passing  from  the  bladder  the  first  portion 
may  be  clear  and  the  remainder  thick.  Sometimes  a 
small  quantity,  consisting  almost  entirely  of  amorphous 
phosphate  of  lime,  may  be  passed  with  considerable 
straining  and  feeling  of  irritation  immediately  after 
the  flow.  Urine  alkaline,  from  either  excess  of  alkaline 
carbonates  or  phosphates,  must  not  be  confounded  with 
true  phosphaturia  when  there  is  an  excessive  excretion 
of  earthy  phosphates.  In  simply  alkaline  urines  there 
may  be  a  deposit  of  earthy  phosphates,  though  there 
need  not  necessarily  be  an  excess.  In  phosphaturia, 
even  with  considerable  excess  of  calcium  phosphate, 
there  is  no  deposit,  and  the  urine  is  often  acid 
(§  113).  The  degree  of  alkalescence  is  determined 
by  neutralising  100  cc.  of  the  urine  by  a  solution 
of  oxalic  acid,  standardised  so  that  1  cc.  =  "01  grm. 
of  sodium  hydrate  ;  the  number  of  cc.'s  of  the 
standard  solution  employed  to  effect  neutralisation 
multiplied  by  "01  gives  the  degree  of  alkalescence  in 
100  parts  ;  and  from  this  the  total  alkalinity  of  the 
twenty-four  hours'  urine  can  be  calculated. 


Chap.  IV.)  AmMONIACAL     UlilNE.  II5 

(3)  Urine  alkaline  from  volatile  alkali  (amnioniiim 
carbonate).  —  Tliis  condition  is  induced  by  disease 
of  the  genito-iirinary  organs,  since  experiments  on 
Jiealtl)y  anijnals  sliow  that  tlie  nrine  does  not  become 
amnioniacal  by  prolonged  retention  in  the  l)ladder,  so 
long  as  that  oi'gan  does  not  become  inflamed,  and  also 
that  the  introduction  of  the  "  ammoniacal  ferment" 
into  the  bladder  of  animals  will  not  cause  decomposi- 
tion of  urea  so  long  as  the  mucous  membrane  remains 
healthy.  Feltz  and  Ritter,  fi-om  observations  made 
on  seventy-eight  persons  suffering  from  different 
diseases,  came  to  the  conclusion  that  the  urine  does 
not  become  ammoniacal  unless  received  into  dirty 
^■essels,  or  mixed  with  products  of  the  decomposition 
from  the  mucous  surfaces  of  the  genito-urinary  appa- 
ratus. In  one  of  their  cases  a  patient  was  taking  0-2 
gramme  of  bichloride  of  mercury  daily,  and  the  urine 
was  analysed  every  day  ;  the  acidity  fell  on  the  ninth 
day  to  -02  gramme,  on  the  tenth  day  it  was  neutral, 
on  the  eleventh  day  it  was  alkaline  and  ammoniacal. 
This  change  in  the  I'eaction  coincided  with  the  appear- 
ance of  a  trace  of  albumin  in  the  urine,  which  was 
turbid,  and  contained  flakes  of  epithelium  and  leuco- 
cytes. In  some  cases  of  scarlet  fever  I  have  noticed 
that  when  albumin  appeared  in  the  urine  the  reaction 
frequently  became  alkaline,  and  crystals  of  ammonio- 
magne.sium  phosphates  were  deposited.  Dr.  Owen 
Rces  has  advanced  a  theory  that  it  is  by  no  means 
necessary  for  ammoniacal  urine  to  depend  on  decom- 
position of  the  urea  ;  he  maintains  it  can  be  formed  by 
the  secretion  of  the  mucous  membrane,  which  owes 
its  alkalinity  to  fixed  alkali,  and  which,  mixed  or 
mingled  with  the  urine,  unites  with  the  acids  of  the 
ammoniacal  salts  and  thus  liberates  the  ammonia.  In 
answer  to  this  view  it  is  sufficient  to  state  that  the 
existence  of  ammoniacal  salts  in  tlie  urine,  except  as 
the   result   of   the   decomposition  of   ui-ea,  has  been 


ii6  Clinical  Chemistry.  [Chap.  iv. 

denied  by  most  chemists,  and  that  if  Dr.  Owen  Rees' 
view  were  correct,  ammoniacal  urine  would  be  more 
frequent  than  it  is,  since  whenever  the  mucous 
secretion  of  the  urinary  passages  was  increased  the 
urine  would  become  ammoniacal.  Clinical  expe- 
rience teaches  us  that  this  is  not  the  case.  At  the 
same  time,  there  can  be  no  doubt  that  the  presence 
of  fixed  alkali  in  urine  greatly  favovirs  ureal  decom- 
position, and  the  process  is  induced  more  rapidly. 
Whenever  the  urine  becomes  ammoniacal,  crystals 
of  ammonio-magnesium  phosphates  are  formed,  which 
either  pass  away  as  gravel  or  are  retained  as  a  calcu- 
lous deposit.  We  distinguish  between  the  reaction 
due  to  fixed  alkali  and  that  of  volatile  alkali  by  the 
fact  that  with  the  former  the  blue  colour  given  to 
red  litmus  does  not  disappear  on  drying,  whilst  with 
the  alkalescence  due  to  ammonia  the  blue  tint  is 
evanescent. 

108.  Colour. — The  nature  of  the  pigment  that 
imparts  the  colour  to  the  urine  has  been  the  subject  of 
much  discussion.  Spectroscopic  analysis  has  recently 
thrown  fresh  light  on  the  subject,  MacMunn  has 
shown  that  human  urine  always  gives  an  absorption 
band  at  F  in  the  same  manner  as  choletelin^  the  pig- 
ment obtained  by  Jaffe  from  bile.  He  thinks  all 
the  colouring  matters  of  the  bile  are  produced  from 
hsematin  by  reduction,  due  to  the  action  of  the  bile 
acids  on  hsemoglobin.  All  the  colouring  matter  of 
the  bile,  including  hsematin,  urobilin  of  biliary  origin, 
bilirubin,  etc.,  are  oxydised  to  clwletelin,  and  there  is 
evidence  to  show  that  blood  serum  contains  this  body 
on  its  way  to  be  excreted  by  the  kidneys.  The  uro- 
bilin of  the  bile  is  produced  in  the  intestine,  and  may, 
in  certain  conditions  of  the  system,  appear  as  such  in 
the  ux-ine,  but  under  normal  conditions  is  oxydised  into 
clwletelin,  which  must  be  considered  one  of  the  chief 
urinary  pigments.     Most  of  the  urinary  pigments  may 


Chap.  I  V.J  l/KINA/n-   P/GMKNTS.  W] 

thus  be  traced  back  to  urobilin  of  l)ili:uy  ori^jjin  ;  but 
there  is  also  evidence  to  show  tliat  some  of  them  are 
derived  from  hivniatin  directly,  and  that  pigments 
derived  from  that  source  may  occasionally  entirely 
i'i'j)lace  the  normal  jiigment.  The  .sjjectroscopic  char- 
acters of  the  ]>ignient  dillei'.  In  febrile  urine  the  black 
band  in  v  is  sharp,  in  normal  ui'ine  it  is  less  marked 
at  tho  edges  and  less  shaded.  The  band  is  well  seen 
in  alcoholic  solutions,  and  is  destroyed  by  the  action 
of  caustic  alkalies.  In  addition  to  the  pigment  above 
described  as  related  to  urobilin  and  convertible  into 
it,  most  urines  contain  a  pigment  allied  to,  if  not 
identical  with,  indican,  and  which  is  commonly  known 
as  uroxanthin.  The  source  of  this  body  is  probably 
from  indol  formed  by  the  decomposition  of  j^roteid 
substances  by  pancreatic  digestion,  since  indican  is 
found  in  the  urine  of  animals  after  the  subcutaneous 
injection  of  indol,  and  also  after  ligature  of  the  small 
intestines  (§  7G).  In  many  diseases  the  amount 
that  appears  in  tlie  urine  is  considerably  increased, 
as  in  diabetes,  dysentery,  the  reaction  stage  of 
cholera,  in  ob.struction,  and  other  aiFections  of  the 
intestines.  Urines  containing  this  substance,  when 
heated  with  strong  acids,  give  rise  to  blue.  gi*eenish, 
and  red  pigments  (the  blue  and  green  urines  some- 
times met  with  in  disease  may  thus  be  referred  to 
indican  in  different  states  of  oxydation) ;  these  some- 
times occur  spontaneously  in  urine.  Urines  con- 
taining much  indican  are  invariably  highly  acid  (and 
this  acidity  inci'eases  on  keeping),  and  they  generally 
deposit  a  considerable  amount  of  uric  acid,  and 
partially  decompose  a  solution  of  sulphate  of  copjjer. 
Whether  this  reduction  is  due  to  the  presence  of  uric 
acid  in  excess,  or  to  the  fact  that  indican  is  a  glu- 
coside,  and  yields  on  decomposition  a  molecule  of 
glucose,  is  not  determined.  Jllelaniti,  a  black  pigment, 
occurs  pathologically  in  the  urine  in  patients  sutiering 


ii8  Clinical  Chemistry.  [Chap.  iv. 

from  melanotic  tumours ;  it  is  sometimes  found  in  the 
urine  of  persons  suffering  from  ague.  It  is  soluble  in 
caustic  potash,  and  can  then  be  decolorised  by  passing 
chlorine  through  the  solution.  The  colour  of  the 
twenty-four  hours'  urine  is  light  amber,  the  urina 
sanguinis  and  urina  cibi  a  golden  amber,  the  urina 
potu  a  pale  straw  colour.  It  must  not  be  forgotten 
that  many  articles  of  diet  and  medicine  impart  a 
colour  to  the  urine.  The  presence  of  blood,  bile, 
albumin,  sugar,  change  the  colour  of  the  urine. 
These  alterations  will  be  considered  under  their 
respective  heads. 

109.  Odour. — Normal  urine  has  an  odour  sui 
generis.  It  is  described  as  aromatic.  Alkaline  urine 
evolves  an  ammoniacal  odour  when  its  alkalinity  is 
due  to  volatile  alkali ;  a  faint  mawkish  smell,  like  that 
of  horses'  urine,  when  alkaline  from  fixed  alkali. 
Diabetic  urine  is  said  to  exhale  a  whey-like  fragrance. 
Urine  containing  cystin  at  first  smells  like  sweet- 
briar,  but  speedily  becomes  horribly  offensive.  In 
certain  forms  of  dyspepsia  the  urine  has  a  sickly 
})enetrating  odour.  Medicines  and  certain  articles  of 
food  often  impart  a  peculiar  odour  to  urine,  as  tur- 
pentine, the  fragrance  of  violets,  and  asparagus,  a 
peculiarly  rank  foxy  odour. 

110.  Urea  CH4N2O. — About  one  ounce  of  this 
body,  or,  if  we  calculate  in  French  measures,  about 
33  grammes  of  this  substance,  are  passed  out  of 
the  body  in  the  urine  in  the  course  of  twenty-four 
hours.  We  have  already  stated  (§  79)  that  urea  is 
isomeric  with  ammonium  cyanate.  With  regard  to  this, 
attention  has  been  called  to  the  fact  that  urea  is  a  much 
more  stable  body  than  ammonium  cyanate,  and  that 
in  the  transformation  of  the  latter  into  the  former, 
energy  is  set  free.  Thus,  ammonium  cyanate  is  the 
type  of  living,  and  urea  of  effete,  nitrogen,  and  the 
conversion  of  the  former  into  the  latter  is  the  image 


Chap.  IV.]  Urea.  119 

of  the  essential  cliangt;  which  takes  place  when  a  living 
prot(U(l  dit's.  It  is  prul)al)h!,  iiion^ovcr,  that  cyanoi^eu 
c<)iii[)ouii(ls  precede  Ww.  forniatioii  of  urea,  and  act 
with  great  niok!cidar  eii(M-gy  till  they  j)ass  into  the 
mure  stabh^  but  ell'ete  form  of  urcsa,  when  they  are 
cast  out  of  tli(!  body.  Urea  thus  represcaits  the  ulti- 
mate product  of  the  nietal)olism  of  the  nitrogenous 
constituents  of  the  food  and  tissues.  In  health,  the 
amount  excreted  is  ])roportionate  to  this  nietaijolisni  ; 
in  disease,  however,  no  such  relationshii)  is  maintained. 
The  amount  is  increased  in  all  acute  diseases,  and  is 
especially  marked  during  pyrexia!  exacerbations.  In 
typhus  fever  the  excretion  is  highest  during  the  first 
^\■eek,  the  excretion  then  bcdng  often  double  that  of 
the  fourth  week,  although  the  patient  during  the  first 
stage  is  on  low  diet,  and  during  the  latter  period  on 
meat  diet.  In  relapsing  fever  the  iirea  is  inci'eased 
during  the  paroxysms,  and  diminished  during  the  in- 
terval. In  enteric  fever,  urea  is  excreted  in  the  largest 
amounts  dui'ing  the  first  week  of  the  disease,  it  then 
gradually  diminishes.  Still  the  quantity  continues  in 
excess  of  the  normal  standard  as  long  as  the  fever 
lasts ;  the  amount  excreted  daily  during  the  disease  is 
not  influenced  by  the  amount  of  diarrhoea.  In  erup- 
tive fevers  as  measles,  small-pox,  and  scarlet  fever, 
urea  is  increased  in  amount  during  the  first  four  days. 
If,  in  the  latter  disease,  kidney  com})lication  sets  in, 
a  sudden  fall  takes  place.  In  intermittent  fevers, 
the  urea  of  the  twenty-four  hours  is  not  markedly 
increased,  but  during  a  paroxysm,  and  just  before  it, 
there  is  a  decided  increase,  followed  by  a  decrease. 
The  reason  of  the  increase  of  urea  accompanying  or 
l)receding  a  rise  of  temperature,  has  been  given  (§  7). 
As  the  liver  is  the  organ  in  which  metabolic  changes 
leading  to  the  formation  of  urea  are  the  most  active, 
though  it  has  now  been  shown  most  conclusively  that 
urea  is  also  produced  largely  from  the  leucin,  the  result 


I20  Clinical  Chemistry.  rchap.  iv. 

of  pancreatic  digestion,  and  from  tlie  kreatin  in  muscles, 
disease  or  disturbance  of  functions  of  that  organ 
especially  affect  the  excretion.  In  acute  yellow  atrophy 
the  urea  is  slightly  increased  at  first,  during  the  hyper- 
semic  stage,  but  rapidly  decreases  as  the  disease  ad- 
vances, and  when  the  liver  cells  are  destroyed,  nearly 
all  trace  may  disappear  from  the  urine,  its  place  being 
taken  by  uric  acid,  leucin,  and  tyrosin,  and  some  ill- 
defined  albuminoid  bodies  resembling  peptones.  In 
hepatic  abscess  and  in  cancer  of  liver  a  notable  diminu- 
tion is  observable.  In  diseases  of  the  kidney,  in  both 
acute  and  chronic  forms  of  nephritis,  the  excretion 
of  urea  is  lessened ;  although  no  relationship  exists 
between  the  discharge  of  albumin  and  excretion  of  urea, 
still  a  more  favoui-able  prognosis  may  be  expressed 
when  the  urea  does  not  progressively  diminish.  In 
the  albuminuria  of  pregnant  women  the  amount 
of  urea  in  the  urine  is  only  slightly  diminished. 
In  a  case  of  Dr.  Maxwell's,  of  Woolwich,  I  found 
urea  in  the  twenty  four  hours'  urine  to  the  amount 
of  27  grammes,  a  little  below  the  normal.  In  a 
case  of  Dr.  John  Williams',  in  the  urine  of  twelve 
hours  immediately  preceding  venesection  the  urea 
was  14-26  grammes,  and  the  albumin  was  4'9 
grammes ;  in  the  twelve  hours'  urine  immediately 
succeeding  venesection,  I  found  urea  15-6  grammes,  and 
the  albumin  2  "6  grammes.  Bleeding,  therefore,  had 
little  effect  on  the  excretion  of  the  urea,  which  in  both 
periods  was  only  little  below  the  normal,  but  it  mate- 
rially reduced  the  amount  of  albumin.  In  diabetes, 
urea  is  always  largely  in  excess,  in  measure  due  no 
doubt  to  the  increased  quantity  of  animal  food  con- 
sumed ;  still  this  does  not  altogether  explain  the  whole 
of  the  increase.  A  sudden  fall  in  the  excretion  is  an 
unfavourable  sign,  as  it  often  is  a  prelude  to  diabetic 
coma,  in  which  state  both  urea  and  sugar  are  excreted 
in  lessened  quantities ;    the  fall  in  the  urea  usually 


M 


Chaj..  IV.]  Ul<r.A.  121 

precedes  that  of  the  su<;ai-.  In  iitcrine  disciiscs  a 
temporary  excess  of  urea  in  the  urine  is  to  be  met 
with.  It  is  said  to  be  increased  botli  before  and  after, 
but  diminished  during,  tlie  menstrual  period.  In  the 
]H'riodic  jaundice  recurring  at  tlie  menstrual  periods 
(icterus  vieiislrnaJis)  urea  is  increased.  In  ])hthisis 
the  exci'etion  of  urea  corresponds  with  the 
pyrexia.  Ila])id]y  growing  cancer  causes  a 
diminution,  a  fall  from  29 •5  grammes  to  as 
low  as  6-9  has  been  recorded.  In  certain 
constitutional  states  urea  is  also  diminished, 
P  u  re  '"^^  ^^^  patients  suflering  from  anaemia, liydriemia. 
Urea,  clironic  alcoholism,  and  syphilitic  cachexia. 
Under  the  term  "  renal  inadequacy,"  Dr. 
Andrew  Clarke  has  described  condition  in  which  only 
a  very  small  quantity  of  urea  is  continuously  passed, 
although  there  is  no  recognisable  disease  present. 
These  cases  improve  on  a  carefully  regu- 
lated dietary.  As  a  converse  to  these  are 
cases  which  habitually  excrete  an  enormous 
amount  of  urea,  together  with  the  other 
urinary  constituents.  Dr.  Prout  termed 
this  condition  azoturia,  though  it  may 
more  aj^propriately  be  termed  polyuria ;  it 
often  precludes  phthisis,  or  may  be  an 
antecedent  condition  of  diabetes  mellites.  (For 
(jualitative  tests  for  urea,  see  §  7.)  For  clinical 
jiurposes  urea  is  often  roughly  estimated  by  the 
])recipitation  of  nitrate  of  urea,  by  adding  an  equal 
volume  of  strong  nitric  acid  to  the  urine ;  if  nitrate 
of  urea  is  thrown  down  without  concentration  of  the 
urine,  then  it  is  said  to  be  in  excess,  if  concentrated 
to  half  its  bulk,  about  normal  ;  if  further  concen- 
tration is  required,  then  less  than  normal.  It  is  needless 
to  point  out  the  fallacy  of  this  method,  since  unless 
the  quantity  of  urine  passed  and  the  specific  gravity 
are    likewise    noted,    urines    containing   absolutely  a 


122  Clinical  Chemistry.  [Chap.  iv. 

considerable  quantity  of  urea  may  be  passed  by  the 
})atient  in  a  very  dilute  form,  whilst  others,  containing 
only  an  ordinary  quantity,  may  be  voided  in  a  concen- 
trated state,  and  give  the  reaction,  and  thus  mislead 
the  physician.  For  accurate  determination,  recourse 
must  be  had  to  volumetric  analysis :  (a)  Liebvjs  inetliod. 
I'or  this  purpose  40  cc.  of  urine  are  taken,  and  freed 
from  albumin  if  present  by  heat  and  filtration,  and 
mixed  with  exactly  the  same  quantity  of  a  solution  of 
barium  hydrate  (2  volumes)  with  barium  nitrate  (1 
volume);  this  precipitates  the  phosphates  and  sulphates; 
a  few  drops  of  solution  of  nitrate  of  silver  are  then 
added,  which  precipitates  the  chlorides.  Set  aside  till 
the  precipitate  has  collected  at  the  bottom  of  the 
beaker,  then  filter,  and  of  the  clear  filtered  solution 
take  20  cc,  reserving  the  remainder  in  case  of  acci- 
dent. This  of  course  represents  10  cc.  of  urine.  Now 
run  into  this  solution,  from  a  burette,  10  cc.  of  stan- 
dardised solution  of  mercuric  nitrate,  stir  the  mixture 
well,  withdraw  a  drop  on  a  glass  rod,  and  let  it  fall  on 
a  drop  of  sodium  carbonate  solution  placed  on  a  white 
plate  or  on  a  flat  porcelain  dish.  If  a  yellow  stain 
occurs  the  process  must  be  repeated  with  the  reserve 
stock ;  but  this  is  ^^nlikely,  unless  the  urea  is  very 
inconsiderable  indeed.  If  there  is  no  stain,  add  5  cc. 
more,  and  then  test  again  ;  if  no  reaction  occurs,  repeat 
the  process  more  cautiously,  adding  1  cc.  at  a  time  till 
a  yellow  stain,  due  to  the  formation  of  hydrated  oxide 
of  mercury,  is  at  last  produced.  Now  as  each  1  cc. 
of  the  standard  solution  of  mercuric  nitrate  is  equi- 
valent to  -01  gramme  of  urea,  the  number  of  cc.'s 
employed  to  produce  the  yellow  stain  indicates  the 
number  of  grms.  present  in  10  cc.  of  urine,  from 
which  the  amount  in  the  twenty-four  hours'  urine  can 
readily  be  deduced.  (5)  Russell  and  West's  method 
is  based  on  the  fact  that  hypobromous  acid  decomposes 
urea   into  water,   carbonic   acid,    or   nitrogen.       The 


Chap.  IV.]  Uric  Acid.  123 

latter  gas  is  collected  alone  in  a  graduated  tul)0,  wliicli 
is  standardised  so  that  eacli  measure  represents  ojio 
gramme  of  urea  in  100  cc.  of  urine.  In  employing 
this  test  for  tlie  detcriiiination  of  urea  in  diabetic 
urines,  it  must  be  remenib(!red  that  grai)e  sugar  in- 
creases tlie  quantity  of  nitrogen  evolved  from  urea  by 
sodium  liypobromite  by  (juite  seven  per  cent.  The 
deficiency  of  nitrogen  yielded  with  pure  solution  of 
urea,  under  the  hyperbromite  test,  is  about  eight  jjer 
cent.,  the  addition  of  glucose,  therefore,  brings  it  uj) 
to  the  theoretic  yield.  This  is  of  little  importance 
unless  the  analyses  are  made  for  purpose  of  comparison 
of  diabetic  with  non-saccharine  urine.  In  making  a 
series  of  observations,  care  must  be  taken  always  to 
secure  the  same  temperature,  as  a  slight  decrease  or 
increase  makes  a  considerable  diflerence  in  the  gas 
volume.  From  non-attention  to  this  important  par- 
ticular, many  discordant  results  have  been  obtained. 
After  considerable  experience  I  have  come  to  the  con- 
clusion that  Liebig's  method  is  not  only  the  most 
reliable,  but  after  a  little  experience  quite  as  readily 
p(!rformed  as  the  other. 

111.  Uric  acid  C^HiNjOs. — "Was  discovered  by 
Scheele  in  1776,  and  was  at  first  thought  to  be  solely 
a  constituent  of  urinary  calculi,  hence  the  term 
lithic  acid  usually  ap[)lied  to  it.  In  1797,  Woollaston 
showed  that  gouty  tophi  were  composed  of  sodium 
urate;  whilst,  in  1848,  Dr.  Garrod  brought  forward 
the  fact  that  in  true  gout  an  excess  of  uric  acid  exists 
in  the  blood  prior  to  and  at  the  period  of  the  attack. 

From  the  circumstance  that  uric  acid  is  a  di-ureide, 
that  is,  by  oxydation  a  molecule  of  uric  acid  can  be 
split  up  into  a  molecule  of  a  non-nitrogenous  acid  and 
two  molecules  of  urea,  it  has  been  assumed  that  when 
the  process  of  oxydation  is  imperfectly  performed 
within  the  body  uric  acid  will  be  found  in  excess  in 
the   blood ;    and    this   assumption    has   been   further 


124  Clinical   Chemistry.  [Chap.  iv. 

strengthened  by  tlie  supposition  that  uric  acid  is  one 
of  the  substances  through  which  each  particle  of 
albumin  passes  before  it  is  thrown  out  of  the  body. 
This  view  has  for  many  years  completely  dominated 
urinary  pathology.  Now,  however,  since  it  has  been 
shown  that  uric  acid  is  not  a  necessary  antecedent 
of  urea,  which  is  largely  formed  from  kreatin  in 
muscle,  and  leucin  and  other  bodies  in  the  alimentary 
canal,  the  view  has  gained  ground  that  uric  acid  in 
the  human  body  in  health  is  only  formed  in  minute 
quantities,  and  that  even  in  disease  it  is  not  formed  in 
anything  like  the  amount  formerly  supposed,  and  that 
when  it  is  deposited  from  the  urine  or  in  the  tissues, 
the  fact  of  the  occurrence  of  such  deposit  may  be 
generally  referred  to  its  insolubility  rather  than 
excessive  production  in  the  system.  It  is  now  taught 
that  while  uric  acid  is  met  with  in  small  quantities  in 
the  large  glands  like  the  spleen,  liver,  etc.,  in  health 
it  is  never  found  in  the  blood  ;  so  that  uric  acid  is 
probably  oxydised  as  soon  as  formed,  and  that  the 
small  quantity  found  in  normal  urine,  only  0*5 
gramme,  or  about  7  grains,  a  whole  day's  excretion, 
is  not  derived  from  the  blood,  but  from  the  kidney, 
which,  instead  of  being  oxydised,  as  is  the  case  with 
other  organs,  passes  away  with  the  secreted  urine.  In 
many  diseases  attended  with  considerable  tissue 
metamorphosis,  the  amount  of  uric  acid  formed  in  the 
large  organs  is  increased,  and  a  portion  not  completely 
oxydised  passes  into  the  blood,  and  froin  thence  into 
the  urine,  though  even  then  the  amount  is  never 
large,  rarely  exceeding  1  -5  grammes  in  the  twenty -four 
hours  as  an  outside  avera,ge  ;  in  these  cases  there  is,  as 
well,  generally  an  increase  ii;i  the  amount  of  urea  ex- 
creted. In  gout  there  may  be  an  increased  production, 
but  most  likely,  as  Dr.  Garrod  suggests,  it  is  due  rather 
to  an  accumulation  in  the  blood,  caused  by  a  resorption 
in  the  uric  acid  formed  in  the  kidney  not  being  excreted 


Chip.  IV.]  Uric  Acid.  125 

Avith  the  urino,  but  takoii  up  by  the  blood  and  carried 
the  round  of  the  circuhition  in  combination  with  soda, 
and  deposited  in  tlie  least  vascular  parts,  the  cartilages 
of  the  joints,  the  cartilages  of  the  ear,  the  straight 
tubules  of  the  kidney,  etc.,  as  sodium  urate.  Uric 
acid  is  the  most  insoluWc  of  all  the  substances  formed 
in  the  body,  requiring  15,000  parts  of  water  for 
solution,  whilst  urea  is  soluble  in  its  own  weight.  It 
is,  therefore,  fortunate  that  those  animals  whose 
urinary  a})paratus  is  not  adapted  for  cari'ying  off  solid 
or  semi-solid  urine  like  birds  and  reptiles,  that  soluble 
urea  replaces  the  insoluble  uric  acid,  otherwise 
calculous  disease  would  be  infinitely  more  common 
than  it  is.  Owing  to  this  insolubility,  whenever  the 
amount  of  water  in  the  urine  required  to  keep  uric  acid 
and  its  salts  in  solution  falls  below  a  certain  point, 
then  uric  acid  or  its  salts  are  deposited.  In  acid  con- 
ditions of  the  urine,  uric  acid  and  its  salts,  unless 
heated,  are  almost  altogether  insoluble,  so  that  when 
the  natural  acidity  of  the  urine  is  at  all  heightened, 
they  are  at  once  deposited.  The  following  summary 
gives  the  chief  conditions  which  lead  to  a  deposit  of 
uric  acid  in  the  urine,  or  its  excessive  elimination 
from  the  body. 

(a)  Deposits  of  uric  acid  or  urates,  not,  however, 
necessai'ily  eliminated  in  excessive  quantities. 

(i)  Absolute  increase  in  the  acidity  of  the  urine. — 
The  occasional  deposit  of  urates  observed  in  winter 
arises  from  this  cause.  The  action  of  the  skin  being 
checked,  the  acidity  of  the  urine  increases  during  cold 
weather.  Similarly  in  many  extensive  cutaneous 
diseases,,  such  as  eczema  and  psoriasis,  uric  acid 
deposits  are  of  frequent  occurrence  ;  also  in  forms  of 
dyspepsia  associated  with  irregular  secretion  of  gastric 
juice. 

(2)  Relative  increase  in  the  acidity  of  the  vriiie. — 
The  deposits  of  urates  frequently  noticed  during  the 


126 


Clinical  Chemistry. 


[Chap.  IV. 


rorms  of  Uric  Acid. 


summer  months  originate  in  tiiis  way ;  tlie  cutaneous 
transpiration  being  increased  in  hot  weather,  the  urine 
is  more  concentrated.  Similai-ly  in  pyrexia,  especially 
rheumatic  fever,  and  in  diar- 
rhoea. Uric  acid  deposits 
alternating  with  sugar  are 
often  caused  in  this  way : 
since  as  the  sugar  disappears 
urination  is  not  so  profuse, 
and  a  relative  increase  in 
the  acidity  of  the  urine  oc- 
curs. This  relative  increase 
may  not  only  be  caused  by  a 
diminution  of  the  water  ex- 
creted, but  from  deficiency  of  the  alkaline  phosphates  ; 
this  condition  is  frequently  met  with  in  the  urines  of 
ill-nourished  or  strumous  children. 

(b)  Uric  acid  eliminated  in  excess,  but  not  neces- 
sarily deposited  from  the  urine. 

(1)  tlric  acid  in  excess  usually  attended  with  a 
diminution  of  the  other  icrinary  constituents  {true 
lithoimia.) — Chiefly  in  diseases  of  the  liver,  such  as 
acute  yellow  atrophy,  cirrhosis,  and  cancer.  In 
diseases  of  the  spleen,  leucocythsemia.  In  scurvy  an 
excess  of  uric  acid  is  generally  observed,  with  a  dimi- 
nution of  urea  and  the  alkaline  phosphates. 

(2)  Uric  acid  in  excess  attended  with  an  increase 
of  the  other  urinary  constituents. — In  functional 
derangements  of  the  liver,  especially  those  brought 
about  by  disturbance  of  the  "nitrogenous  equilibrium" 
by  the  ingestion  of  too  much  animal-  food.  As  a 
condition  antecedent  to  the  development  of  phthisis 
or  cancer,  and  sometimes  of  diabetes,  or  preceding  the 
outbreak  of  such  constitutional  conditions  as  syphilis, 
scrofula,  and  of  gout  in  its  early  attacks. 

Uric  acid  when  deposited  from  the  ui'ine  in  a  free 
state  resembles  grains  of  cayenne  pepper,  and  presents 


Chap.   I  v.)  UkIC   AcfD.  127 

iinilcr  (Iio  iiiicrnscope  tlin  appoaranco  sliowii  in 
Fig.  6.  The  l)ases  met  with  in  urine  in  combi- 
nation with  uric  acid  are  chiefly  those  of  soda 
and  ammonia,  though  lime  is  sometimes  present. 
They  are  thi'own  down  as  a  granular  deposit,  but 
amidst  the  small  granules  are  semi-crystalline  bodi(!S 
depicted  (Fig.  7).  Both  uric  acid  and  its  salts 
are  freely  sohible  in  alkaline  solutions;  this  is  an 
important  point  to  remember,  not  only 
as    regards    treatment,   but   as   regards  i]),  ^ 

their  detection  in  the  urine,  since  their      --^st:^ 
ciystals    are     frequently    modified     in     fc   w,       .*^ 
shajie,     may    be     mistaken     for    other      -X^i^    "^ 
urinary    deposits  ;     the    fact    of    their 
dissolving    in    litpior    potasste    at   once   ^*|j  ^'u7ate'™of 
identifies  them.      Uric  acid  and  ui'ates      Sodium     (a); 
yield  a  magnificent  purple  when  heated      mouia  (6). 
with   nitric   acid,   and   the  dry   residue 
is    touched    with    aunnonia    (§  64).      When    a    con- 
centrated   solution  of  urates  is   treated   with   sti-ong 
nitric  acid,  the  uric  acid  is  liberated  in  an  amorphous 
form,  in  which  it  is  more  soluble  than  in  its  crystalline 
state ;    on    standing  it  slowly    recombines    with    the 
sodium  salts  in  the  urine,  and  is  deposited  as  urate  of 
sodium.      The  peculiar  bulky  gelatinous  preci})itate, 
soluble   when  heated,   some  concentrated  urines  give 
when  tested  with  nitric  acid  for  albumin,  is  due  to  the 
uric  acid  being  liberated  in  this  amorphous  form. 

Uric  acid  is  determined  quantitatively  by  precipi- 
tating the  in-ic  acid  from  the  urine,  and  by  collecting 
and  weighing  the  cr3'stals.  For  this  purpose  place  1 00 
cubic  centimetres  of  filtered  urine  (having  previously 
dissolved  any  deposited  urates  by  heating)  in  a  glass 
vessel,  and  add  10  cubic  centimetres  of  strong  hydro- 
chloric acid ;  set  aside  in  a  cool  dark  ])lace  foi'  twenty- 
four  hours.  Then  carefully  collect  crystals,  and  transfer 
them  to  a  watch-glass,  wash  thoroughly  with  dilute 


128  Clinical  Chemistry.  ichap.  iv. 

hydrochloric  acid,  and  then  transfer  them  to  a 
weighed  filter.  Dry  in  hot-air  bath  and  weigh.  The 
increase  in  weight  over  that  of  the  filter  will  give 
the  amount  of  uric  acid  in  100  cubic  centimetres  of 
urine. 

If  the  urine  is  of  low  specific  gravity,  below  1-015, 
it  should  be  concentrated  to  one-third  its  bulk,  if 
below  1-010  to  one-half. 

112.  Oxalate  of  lime  CaC204. — An  extremely 
small  quantity  of  oxalic  acid  is  met  with  in  all 
urines,  chiefly  in  combiiiation  with  ammonia  and  soda, 
forming  soluble  salts.  In  several  morbid  states  of  the 
system,  however,  oxalic  acid  appears  in  the  urine  as 
oxalate  of  lime,  in  which  case  it  either  comes  away  as 
a  fine  crystalline  deposit,  or  else  is  retained  in  the 
urinary  passages  to  lay  the  foundation  of  a  calculus 
(mulberry  calculus).  Few  subjects  in  uiinary  patho- 
logy have  excited  keener  controversy  than  that 
relating  to  the  causes  tending  to  produce  deposits  of 
oxalate  of  lime  crystals  in  urine.  The  view  has  been 
generally  held  that  oxalate  of  lime  in  urine  was 
simply  derived  from  the  decomposition  of  uric  acid 
after  it  had  been  passed,  and  that  the  presence  of 
oxalate  of  lime  in  the  urine  meant  nothing  more  than 
increased  excretion  of  uric  acid.  This  view  was  based 
on.  the  assumption  that  oxalic  acid  represented  the 
imperfect  oxydation  of  uric  acid.  It  will  be  seen, 
however,  from  the  following  table,  that  so  far  from 
oxalic  acid  being  a  product  of  imperfect  oxydation  of 
uric  acid,  it  is  only  obtainable  by  oxydation  being 
carried  to  its  ultimate  stage  :  thus 

Uric  acid.  Alloxan.  Urea. 

C5H4NA  -h  H,0  +  0  =  C,H,NA  +  CH.N^O 
and 

Alloxan.  Mesoxalic  acid.  Urea. 

C.H^NA  +  2H2O  =  CaH^Os  +  CH,N,0; 


Ch.ip.  IV.)  Calcium  Oxalate.  129 

and  mesoxalic  acid  by  further  oxydation  yields  carbonic 
acid  and  oxalic  acid.  It  is,  therefore,  manifestly  in- 
correct to  speak,  as  most  writers  on  urinary  pathology 
have  done,  of  oxalic  acid  as  the  imperfectly  oxydised 
product  of  uric  acid ;  on  the  contrary,  oxalic  acid  is 
only  obtained  from  uric  acid  by  oxydation  being  carried 
to  its  ultimate  stage.  Now  within  the  body,  under  the 
influence  of  increased  oxydation,  this  reduction  of  uric 
acid  may  occur ;  but  as  a  considerable  quantity  of 
oxygen  is  required  to  etfect  the  reduction,  and  as  the 
clinical  and  pathological  conditions  in  which  we  meet 
with  oxalate  of  lime  in  the  urine,  do  not  point  to 
increased  oxydation  going  on  within  the  body,  but  the 
reverse,  it  is  manifest  that  only  a  small  proportion  of 
the  oxalic  acid  can  be  derived  from  this  source.  Again, 
we  stated,  when  speaking  of  uric  acid,  that  recent 
views  point  to  the  conclusion  that  even  in  disease  the 
amount  of  uric  acid  formed  in  the  body  is  not  great, 
so  that  no  one  who  has  observed  the  enormous  amounts 
of  oxalic  acid  often  passed  into  urine  in  a  single  day, 
or  as  it  exists  in  calculi,  can  believe  that  such  abun- 
dance could  ever  come  from  so  small  an  origin.  The 
view  now  held  is  that  oxalic  acid  is  derived  from  a 
variety  of  sources,  and  is  found  in  urine  under  a 
variety  of  clinical  and  pathological  conditions.  Thus 
it  may  be  derived  (1)  directly  from  food  by  the  inges- 
tion of  substances  containing  oxalate  of  lime,  such  as 
certain  fruits  and  vegetables,  rhubarb,  sorrel,  tomatoes, 
onions,  turnips,  etc.  ;  (2)  indirectly  from  food,  as  by 
incomplete  oxydation  of  the  saccharine  amylaceous  and 
oleagineous  principles  of  food,  which,  before  their  final 
conversion  into  carbonic  acid  and  water,  yield  several 
intermediary  non -nitrogenous  acids,  of  which  the  chief 
are  gly collie,  lactic,  and  oxalic  acids  ;  (3)  from  increased 
tissue  metabolism  ;  this  is  probably  the  most  frequent 
cause  for  the  pathological  appearance  of  oxalate  of  lime 
in  the  urine.  The  urines  in  these  cases  are  generally 
J 


I3P  Clinical  Chemistry.  [Chap.  iv. 

of  a  deep  orange  colour,  of  high  average  specific  gravity, 
with  an  excess  of  urea  and  phosphoric  acid,  and  are 
usually  turbid  with  mucus  and  urates,  while  the 
deposits  of  oxalates  are  not  usually  persistent,  often 
disappearing  for  a  few  days,  to  return  again  in  great 
abundance.  The  explanation  of  its  appearance  being, 
that  the  process  of  oxydation  within  the  body,  under 
circumstances  of  increased  tissue  metabolism,  is  only 
sufficient  to  reduce  a  certain  quantity  of  non-nitro- 
genous fatty  acids  formed  within  the  body  to  their 
lowest  term  of  carbonic  acid,  and  consequently  oxalic 
acid,  which  is  one  of  the  series,  appears  in  the  urine. 
(4)  From  the  mucus  of  the  urinary  passages.  A  veiy 
ingenious  hypothesis  has  been  advanced  by  Meckel  to 
account  for  this  formation  of  oxalate  of  lime  in  mucus, 
by  assuming  that  the  mucous  membrane  of  the  urinary 
passages  becomes  the  seat  of  a  specific  catarrh.  In 
this  catarrh  a  tough  adhesive  mucus  is  secreted,  which 
has  a  tendency  to  undergo  acid  fei'mentation,  and  in 
which  oxalate  of  lime  appears  when  such  fermentation 
occurs.  At  first  this  oxalate  of  lime  mucus  is  of  gela- 
tinous consistence,  but  gradually  it  takes  up  more  and 
more  oxalate  of  lime  from  the  decomposed  urine,  and 
thus,  growing  more  and  more  firm,  a  stony  concretion 
is  at  length  formed.  The  large  and  numerous  crystals 
of  oxalate  of  lime  so  frequently  observed  in  the  urine 
of  persons  suffering  from  spermatorrhoea  are  most 
probably  derived  from  the  mucus  of  the  genito-urinary 
passages ;  (5)  from  excess  of  acid  in  the  system  fi'om 
the  increased  formation  of  lactic  and  butyric  acids  in 
intestines,  the  result  of  fermentative  changes.  These 
acids  absorbed  from  the  intestinal  canal  into  the  circu- 
lation being  in  excess,  their  reduction  into  carbonic 
acid  is  incompletely  performed,  and  so  the  intermediate 
acid,  oxalic,  appears  in  the  urine  in  combination  with 
lime.  The  urine  is  usually  of  a  pale  greenish  colour, 
and  the  quantity   passed  in   the   twenty-four   hours 


Chap.  IV.)  Fnosr//ATKS.  131 

normal  in  quantity  and  specific  gi'avity.  Its  chief 
characteristic  is  the  deposit  of  crystals  of  oxalate  of 
lime,  which  are  found  most  abundantly  in  the  morning 
mine  passed  on  first  rising.  Owing  to  the  presence  of 
these  crystals  causing  irritation  of  the  mucous  mem- 
brane of  the  bladder,  micturition  is  frequent  and 
urgent,  though  the  quantity  of  urine  passed  is  not 
large.  Traces  of  sugar  are  not  infrequently  present, 
and  the  urine  occasionally  contains  an  excess  of  i)hos- 
phate  of  lime.  This  condition  of  urine  is  generally 
associated  with  excessive  flatulence  (flatulent  dys- 
pepsia), chiefly  connected  with  the  small  intestine, 
and  apparently  the  result  of  intestinal  catarrh,  and 
there  is  usually  great  mental  depression. 

Crystals  of  calcium  oxalate  are  to  be  recognised  in 
urine  by  their  peculiar  letter  envelope  shape  a  (Fig.  8), 
sometimes  as  mere  diamond  points,  and  often  as  dumb- 
bells c.  In  the  latter  case  the  ^         ^ 
oxalate  of  lime  is  probably                 ^  gj     /^S^"^ 
derived    from    the    urinary                ^  ^      R\  Ql  '^ 
passages.     The  crystals  dis-         4^      ^^ 
solve  in  mineral  acids,  but     ^0^  c      /^ 
not  in  acetic  or  oxalic  acids,           "          &  ^Q)  ^  ^4\ 
which  serves  to  distinguish                       (^  /^,  ^^ 
them    from    crvstalline  de-                              ^^ 
posits  of  the  Earthy  phos-      ^'^-  ^•-^''^Sit^!  ^"^"'"^ 
phates.     They  ai'e  insoluble 

in  alcohol  and  water.  Under  the  blow-pipe  they  ai-e 
reduced  to  carbonate  of  lime,  and  the  residue  eflfer- 
vesces  on  the  addition  of  acid.  [See  Urinary  calculi.) 

113.  Phosphoric  acid  H3PO4.  —  The  amount 
of  phosphoric  acid  passing  out  of  the  system  in  the 
course  of  the  twenty -four  hours  averages  from  2 '5 
grammes  to  3-5  gi-ammes,  and  is  distributed  among  the 
four  bases,  potash,  soda,  lime,  and  magnesia,  in  the 
proportion  of  about  two-thirds  combined  with  the 
alkaline  oxides  and  one-third  with  the  oxides  of  the 


132  Clinical  Chemistry.  [Chap.  iv. 

earths.  The  alkaline  phosphates  are  extremely  soluble, 
and  therefore  are  never  deposited  from  the  urine.  On 
the  other  hand,  the  earthy  phosphates  are  only  soluble 
in  acid  solutions,  so  that  when  the  urine  becomes 
neutral  or  alkaline,  they  are  deposited.  Thus  it  hap- 
])ens  that  a  deposit  of  the  earthy  phosphates  is  by  no 
means  an  indication  that  they  are  in  excess,  any  more 
than  the  fact  that  no  deposit  is  present  is  an  assur- 
ance that  they  are  being  excreted  in  normal  amount. 
So  long  as  the  urine  remains  acid,  a  considerable 
quantity  of  phosphoric  acid  may  be  passing  out  of  the 
system  without  giving  evidence  of  its  presence,  whilst 
if  the  urine  from  any  cause  becomes  alkaline,  a  deposit 
at  once  occurs,  although  the  phosphoi'ic  acid  may  not 
be  eliminated  in  excess. 

(1)  Excess  of  j)hosphoric  acid,  the  salts  of  v)Mch 
are  not  necessarily  deposited.  This  condition  has 
long  been  recognised  by  writers.  The  amount  of 
phosphoric  acid  is  enormously  increased,  often  rising 
from  3  grammes  to  as  much  as  8  or  10  grammes  in 
the  twenty-four  hours.  It  is  chiefly  in  combination 
with  lime  and  magnesia,  though  the  soluble  phos- 
phates are  also  increased,  but  not  to  the  same  extent. 
The  discharge  of  urine  is  also  greatly  increased,  and 
so  is  the  excretion  of  urea.  The  urine  may  remain 
acid  throughout  the  course  of  the  disease,  and  conse- 
quently may  be  unattended  with  deposit ;  but  when 
it  becomes  alkaline,  which  it  frequently  does,  bulky 
white  deposits  of  amorphous  calcium  phosphate  are 
thrown  down.  The  alkalinity  of  the  urine  in  these 
cases  is  due  to  an  excess  of  the  alkaline  carbonate, 
and  when  it  is  persistent  the  case  is  usually  ex- 
tremely obstinate.  The  pathology  of  this  condition 
is  not  understood,  but  it  seems  to  depend  on  a  pecu- 
liar state  of  the  nervous  system.  The  increased 
elimination  may  be  temporary  in  character  and 
moderate   in   amount.     Such  cases   usually  occur  in 


Chap  iv.i  Pi losr HATES.  133 

persons  who  liave  uiidorgone  nnicli  niccnt  anxiety  or 
mental  strain.  In  tliis  form  it  often  precedes  the 
onset  of  phthisis.  Witli  regard  to  this,  Marcet's 
analysis  of  pulmonary  tissue  in  consumj^tion  has  an 
important  bearing,  since  lie  has  shown  that  a  con- 
siderable reduction  of  phosphoric  acid  and  potash  takes 
place,  in  the  soluble  tissue  and  nutritive  material 
of  the  diseased  as  compared  with  the  healthy  lung 
tissue.  Or  the  increased  elimination  of  phosphoric 
acid  may  be  excessive  and  persistent,  the  disease 
running  a  course  like  saccharine  diabetes,  into  which, 
indeed,  it  often  passes,  but  without  the  ai)pearance  of 
sugar. 

(2)  Deposits  of  2')hos]')hale  of  lime,  not,  however, 
necessarily  attended  ivith  excessive  elimination.  In 
these  cases  the  urine  is  alka- 
line from  hxed  alkali.  The 
urine  is  turbid  or  whey-like 
from  the  presence  of  phos- 
phate of  lime,  which  deposits  —p^  /- 
on  standing  as  amorphous  >s  '^ 
granules.  vSometimes,  however, 
the  phosphate  of  lime  is  preci- 
pitated in  the  form  of  fine  ^^^^^""""3=5*^ 
acicular  crystals  (Fig.  9),  much 

1  T    ^  e    ^  £      i''S.  9— <^rystals  of  Calcium 

resembling     some     lorms    or  Phosphate. 

lU'ic  acid;  they  can  be  dis- 
tinguished from  these  by  their  insolubility  in  liquor 
j)otass8e,  and  solubility  in  hydrochloric  acid.  This 
form  of  urine  is  not  infrequently  met  with  in 
persons  convalescent  from  febrile  diseases ;  and,  in 
certain  forms  of  dyspepsia,  deposits  of  phosphates 
alternating  with  deposits  of  urates  and  uric  acid  are 
often  observed.  Rickety  children  often  pass  urine 
thus  alternating  in  character.  From  the  frequency 
with  which  phosphatic  deposit  occurs  in  this  disease, 
it  was   eiToneously  held    that   the    phosphates   were 


134  Clinical  Chemistry.  [Chap,  iv, 

in  excess ;  this  is  now  shown  to  be  an  firc^fc^  the 
amount  of  earthy  phosphates  not  being  increased 
in  rickets.  Alkaline  urine,  when  passed  into  a  dirty 
chamber  vessel,  often  forms  an  iridescent  scum  on  the 
surface,  owing  to  the  formation  of  crystals  of  arnrnonio- 
rnagnesium  phosphate,  caused  by  decomposition  of 
urea,  which  are  minced  with  granules  of  calcium 
phosphate. 

(3)     Depoaits  of  o/raraordo  -  raagnesium  j)Ji.osphoM 
{triple  phosphate)    Mgf XH^jPO^  +  6IL,0.      We   have 
seen  (page  115)  that  when  the  urine  is  alkaline  from 
the  presence   of  volatile  alkali 
fammonia)  we  have,  in  addition 
to  the  deposit  of  calcium  phos- 
phate, a  crystalline   precipitate 
of     magnesium    phosphate     in 
combination     with      ammonia. 
This     salt     is     usually    called 
triple-phosphate.      The  crystals 
Vi-4.  10.— Crystals  of  Am-     ^^e  met  in  different  forms,  but 
'  monio-ma^nesium.  the  most  charncteristic  is  that  of 

triangular  prisms  f«,  Fig.  10). 
It  is  sometimes  deposited  as  feathery  crystals  {h,  Fig. 
10).  This  is  especially  the  case  when  the  urine 
has  been  artificially  rendered  alkaline  by  the  addi- 
tion of  ammonia.  These  crystals  are  sometimes 
met  with  in  slightly  acid  urine.  In  these  cases 
it  is  probable  that  crystals  have  been  formed 
originally  in  alkaline  urine  in  the  bladder,  but 
which  has  been  rendered  slightly  acid  by  subsequent 
additions  of  acid  urine  from  the  kidney,  before  the 
mixed  urine  is  passed  ;  or  it  may  be  that,  subsequent 
to  emission,  the  urine  which  is  passed  acid  undergoes 
ammoniacal  decomposition  on  its  upper  surface  with  the 
formation  of  these  crystals,  while  the  bulk  of  the 
urine  remains  acid.  It  has  also  been  suggested  that 
the  acid  reaction  in  these  cases  depends  upon  some 


Chap.  IV.]  Phosphates.  135 

s;ilt  which  reddens  litmus  paper,  but  whicli  i«  not  a 
free  acid. 

The  quantitative  estimation  of  phosphoric  acid  is 
performed  as  follows  :  Take  100  cubic  centimetres  of 
urine  and  add  10  cubic  centimetres  of  saturated  sodium 
acetate  solution  ;  divide  into  two  portions  of  55  centi- 
metres ;  each  portion,  of  course,  represents  50  cubic 
centimetres  of  urine.  Reserve  one  portion  in  case  the 
process  has  to  be  repesited.  Heat  the  other  to  100'  C, 
and  then  from  a  burette  add  3  cc.  of  standard 
solution  of  uranic  nitrate;  then,  after  nii.\ing  well  with 
a  glass  rod,  touch  a  drop  of  solution  of  pota.ssium 
ferrocyanide,  which  is  placed  in  a  white  dish,  with 
the  wet  end  of  the  glass  rod.  If  a  reddish-brown 
colour  is  developed,  then  too  much  standard  solution 
hits  been  used,  and  the  process  must  be  repeated 
with  the  reserved  sample;  but  this  is  not  likely  to 
be  the  case,  unless  the  quantity  of  phosphates  is  very 
much  below  normal.  If  no  brown  stain  is  developed 
then  add  1  cc.  more  of  the  standard  solution,  and  after 
each  addition  touch  the  ferrocyanide  of  potassium 
solution  with  the  stirring  rod  ;  when  the  brown  stain 
is  developed  record  the  nuniber  of  centimetres  of  the 
standard  solution  that  have  been  used.  Suppose  the 
coloration  is  given  with  18  cc,  but  not  witli  17  cc, 
then  take  the  reserve  sample,  heat  it  and  run  into  it 
17  cc.  of  standard  solution;  then  only  add  \  centi- 
metre at  a  time,  and  you  will  tind  exactly  the  amount 
required  to  give  the  brown  reaction,  which  may  be 
just  over  17  cc,  or  just  below  18  cc.  Suppose  it  is 
17-5  centimetres,  then,  as  each  cubic  centimetre  of  the 
standard  solution  is  equivalent  to  '005  gramme  of 
phosphoric  acid,  then  17o  x  005  gives  the  amount  of 
phosphoric  acid  in  50  cc.  of  urine,  from  which  it  is 
easy  to  deduce  the  amount  in  the  twenty-four  hours' 
urine.  This  process  gives  the  total  amount  of  phos- 
phoric acid  in  combination  with  alkaline  as  well  as 


136  Clinical  Chemistry.  [Chap.  iv. 

the  earthy  bases.  In  order  to  find  how  much  phos- 
phoric acid  is  in  combination  with  each,  we  must  first 
get  the  total  amount  of  phosphoric  acid  by  the  process 
described  above,  and  then  proceed  to  determine  the 
phosphoric  acid  in  combination  with  the  earths  sepa- 
rately. This  done,  we  deduct  the  amount  of  earthy 
phosphates  from  the  total  phosphoric  acid,  the  difier- 
ence  being  the  alkaline  phosphates.  To  calculate  the 
earthy  phosphates  separately,  take  100  cubic  centi- 
metres of  urine,  and  add  20  cubic  centimetres  of 
liq.  ammonia,  set  aside  for  twenty-four  hours. 
Filter  ofi"  the  precipitated  phosphate  of  lime  and 
ammonio  -  magnesium  phosphate,  and  wash  them 
thoroughly  with  dilute  liq.  ammonia.  Then  dissolve 
the  precipitate  by  means  of  5  cc.  of  strong  acetic 
acid,  and  place  the  filter  and  the  acid  solution  together 
in  a  beaker  and  add  distilled  water  up  to  90  cc. 
Then  add  10  cubic  centimetres  of  saturated  solution  of 
sodium  acetate.  Pilter ;  divide  the  filtrate  into  two 
equal  parts,  each  of  which  represents  the  amount  of 
earthy  phosphates  in  50  cc.  of  urine.  Reserve  one 
portion;  with  the  other  proceed,  after  heating  to 
100°  C,  to  apply  the  standard  solution  of  uramic 
nitrate,  as  in  preceding  process.  The  number  of  cubic 
centimetres  of  the  solution  used  will  give  the  amount 
of  phosphoric  acid  in  combination  with  earthy  bases, 
lime,  and  magnesia,  in  50  cc.  of  urine. 

114.  Hydi'ocliloric  acid  HCl  appears  chiefly  in 
the  urine  as  sodium  chloride.  Barral  has  shown  that 
the  quantity  of  sodium  chloride  excreted  with  the 
urine  does  not  quite  correspond  with  the  amount 
taken  with  food,  about  one-fifth  being  decomposed  by 
acid  potassium  phosphate  to  form  potassium  chloride 
and  acid  sodium  phosphate.  In  acute  febrile  diseases 
the  amount  excreted  by  the  urine  is  rapidly  dimi- 
nished, especially  in  diseases  attended  with  exudation, 
as  pneumonia,  pleurisy,  and  rheumatic  fever ;  as  the 


Chap.  IV.]  Chlorides.  137 

disease  declines  the  chlorides  return  to  the  normal 
excretion,  and  during  convalnscenco  often  exceed  it. 
The  avei.ige  amount  excreted  in  the  twenty-four  hours 
by  a  healtliy  adult  may  be  reckoned  a.s  ranging  from 
5  to  8  grnis.,  varying,  of  course,  with  the  quantity  of 
food.  Chlorine  may  be  estimated  volumetrically  by  two 
processes  :  by  silver  nitrate,  or  by  mercuric  nitrate. 
The  latter  is  the  simplest  and  most  reliable  ;  .00  cubic 
centimetres  of  urine,  freed  from  albumin  if  present,  are 
to  be  precipitated  by  tlie  addition  of  an  equal  quantity 
of  saturated  baryta  solution  (1  volume  barium  nitrate, 
2  volumes  barium  hydrate),  and  then  filtered.  To  the 
solution  add  giadually  a  standardi-sed  solution  of  mer- 
curic nitrate;  at  first,  the  white  precipitate  formed  after 
each  addition  of  the  mercuric  nitrate  solution  disap- 
pears on  shaking.  When,  however,  all  the  chloride 
present  in  the  urine  has  been  converted  into  mercuric 
chloride,  then  the  mercuric  nitrate  combines  with  the 
urea  and  forms  an  insoluble  compound.  The  solution 
of  mercuric  nitrate  iised  for  estimating  chlorine  is 
weaker  than  that  used  for  e.stimating  urea.  It  is 
standardised  so  that  1  cc.  =  '01  grm.  sodium  chloride. 
The  number  of  cubic  centimetres  used  to  produce  a 
permanent  precipitate  in  50  cubic  centimetres  of  urine 
indicates  the  amount  of  chloride  of  sodium  present 
in  that  amount. 

115.  Siilplniric  acid  H„SO.,.  —  Only  a  small 
portion  of  the  sulphur  introduced  into  the  body  with 
the  food  ajjpears  in  the  urine,  a  considerable  portion 
passing  off'  by  the  lx)wels  and  some  by  the  skin,  in  the 
perspiration,  hair,  nails,  and  cuticle.  Probably,  during 
fasting,  the  sulphuric  acid  which  appears  in  the  urine 
is  derived  from  the  sulphur  of  the  albuminous  consti- 
tuents of  the  tissues,  and  thus  the  amount  of  sulphuric 
acid  in  the  urine  may  be  taken  as  the  measure  of  the 
metabolism  of  the  sul))liur  compounds  during  fasting. 
In  rheumatic  fever  and  pneumonia  the  sulphuric  acid 


138  Clinical  Chemistry.  [Chap.  iv. 

is  often  found  considerably  increased  without  any 
increased  ingestion  of  sulphur- yielding  food.  When 
carbolic  acid  is  taken  or  absorbed  in  large  quantities 
into  the  system  the  sulphates  disappear,  being  con- 
verted into  sulpho-carbolates.  The  quantity  of  sul- 
phuric acid  in  the  twenty-four  hours'  urine  is  about 
2  "5  to  3  grammes.  To  estimate  it  quantitatively  take 
50  cubic  centimetres  of  urine,  add  a  few  drops  of  hydro- 
chloric acid  in  order  to  insure  complete  precipitation 
of  the  sulphate,  then  add  a  standardised  solution  of 
.barium  chloride,  1  cubic  centimetre  at  a  time,  till  a 
precipitate  of  barium  sulphate  is  no  longer  formed, 
then,  as  1  cc.  of  barium  solution  is  equivalent  to  "01 
gramme  of  sulphuric  acid,  the  number  of  centimetres 
employed  indicates  the  amount  of  sulphuric  acid  in 
50  cubic  centimetres  of  urine.  The  sulphur  in  the 
body,  however,  is  not  all  oxydised  into  sulphuric  acid, 
and  a  small  quantity  passes  into  the  urine  in  a 
partially  oxydised  state.  In  health  about  0'4  gramme 
of  unoxydised  sulphur  passes  into  the  urine.  In 
disease,  especially  of  the  liver,  this  amount  is  in- 
creased. In  order  to  determine  the  amount,  first 
ascertain  the  quantity  of  sulphuric  acid  present, 
then  evaporate  an  equal  portion  of  the  urine  and 
deflagrate  with  potassium  nitrate ;  this  oxydises  the 
unoxydised  sulphur  into  sulphuric  acid  ;  to  ascertain 
the  amount  of  this,  test  with  the  standardised  barium 
chloride  solution.  The  amount  given  will  be  higher 
than  when  the  estimation  was  made  for  sulphuric 
acid  alone.  The  difference  represents  the  amount  of 
unoxydised  sulphur  converted  into  sulphuric  acid. 

116.  Hippuric  acid  CgHglSTOg.  —  This  sub- 
stance is  a  normal  constituent  of  human  urine,  the. 
quantity  passed  in  the  twenty-four  hours  under  or- 
dinary circumstances  varying  from  0'8  to  1  gramme. 
Weisman  gives  1'17  grms.  as  the  normal  daily  quan- 
tity excreted.     The  excretion  is  greatly  augmented 


Chap.  IV.)  JIippuRic  Acid.  139 

by  a  vegetable  diet,  and  especially  by  such  vegetable 
substances  as  benzoic  acid,  cranberries,  blackberries, 
and  iilunis.  Consequently,  we  are  not  surprised 
to  find  a  considerable  quantity  in  the  urine  of  all  her- 
bivorous animals ;  thus  cows  urine  contains  1  per 
cent.,  and  horse's  urine  0-38.  In  these  animals  hip- 
puric  acid  often  undergoes  oxydation  in  the  system, 
and  is  converted  into  benzoic  acid,  which  appears  in 
the  urine  ;  thus  horses  at  rest  pass  urine  free  from 
benzoic  acid  and  containing  the  standard  quantity  of 
hippuric  acid,  but  when  put  to  hard  work  the  hippuric 
acid  diminishes  and  benzoic  acid  appears.  Kiihne  has 
observed  that  benzoic  acid  given  to  patients  suftering 
from  disease  of  the  liver  passes  unchanged  into  the 
urine  instead  of  being  converted  into  hippuric  acid, 
which  would  have  been  the  case  under  ordinary 
circumstances.  Fi*om  this  fact  he  has  assumed  that 
hippuric  acid  is  derived  from  the  vegetable  aromatic 
constitu.  nts  of  our  food,  and  the  place  of  their  trans- 
formation is  the  liver.  Benzoic  acid,  given  internally, 
is  said  to  diminish  the  excretion  of  uric  acid,  whilst 
hippuric  acid  is  increased.  The  excretion  of  hippuric 
acid  is  increased  in  all  febrile  affections,  also  in 
diabetes.  The  crystals  are  semi-transparent  rhombic 
plates,  insoluble  in  cold  water,  but  extremely  soluble 
in  solutions  of  sodium  phosphate.  Boiled  with  strong 
hydrochloric  acid,  they  decompose  into  benzoic  acid 
and  glycocin  ;  the  latter  crystallises  out  on  cooling.  To 
obtain  hippuric  acid  from  urine,  evaporate  1,000  cubic 
centimetres  of  urine  to  near  dryness,  triturate  the 
residue  with  clean  sand,  and  add  60  cubic  centimetres 
of  hydrochloric  acid  ;  finally  extract  with  alcohol.  The 
acid  alcoholic  solution  is  neutralised  with  soda  ley, 
and  evaporated  to  a  syrupy  consistence  with  a  small 
quantity  of  oxalic  acid,  the  residue  dried  in  a  water 
bath  and  treated  with  a  large  quantity  of  ether  con- 
taining 20  per  cent,  of  alcohol.     When  the  residue  is 


140  -      Clinical  Chemistry.  [Chap.  iv. 

thoroughly  exhausted,  the  alcoholic  etherial  solution 
is  evaporated  and  the  crystalline  residue  treated  with 
a  sokition  of  milk  of  lime,  and  the  resulting  precipi- 
tate removed  by  filtration.  The  nitrate  is  concentrated 
and  hydrochloric  acid  added ;  after  standing  some 
hours  hippuric  acid  will  crystallise  out.  The  crystals 
are  collected  on  a  weighed  filter,  dried  and  weighed ; 
the  weight  gives  the  quantity  of  hippuric  acid  in  the 
amount  of  urine  examined. 

117.  Kreatiniu  04117^30. — This  base  is  con- 
stantly present  in  human  urine  ;  according  to  Neu- 
bauer,  the  quantity  passed  into  the  urine  in  twenty- 
four  hours  averages  0'6  to  1'3  grammes.  It  is  de- 
rived from  the  decomposition  of  kreatin  in  the 
blood  ;  in  no  case  has  it  been  obtained  as  a  primary 
product  of  decomposition  from  any  of  the  tissues. 
Nawrocki  has  shown,  by  experiments,  that  it  does  not 
occur  in  muscular  tissue  either  at  rest  or  when 
tetanised.  The  crystals  form  oblique  rhombic  prisms, 
soluble  in  boiling  water  and  in  1 2  parts  of  cold  water. 
It  is  an  extremely  powerful  base,  gives  an  alkaline 
reaction  with  test  paper,  and  forms  well-defined  basic 
double  salts  with  zinc  chloride  and  silver  nitrate. 

ABNORMAL    CONSTITUENTS    OF    URINE. 

118.  AJbumiii.  —  Various  proteid  substances 
appear  in  urine,  the  result  of  manifold  pathological 
conditions. 

(1)  Serum  albumin  is  the  form  met  with  in 
Bright's  disease,  in  many  depraved  conditions  of  blood, 
in  purulent  discharges  from  the  genito-urinary  tract, 
and  occasionally  in  persons  apparently  healthy,  under 
the  influence  of  undue  physiological  stimuli,  such  as 
excessive  muscular  exertion,  excitement,  or  the  inges- 
tion of  unsuitable  food,  etc.  It  is  now  generally 
accepted  that  the  Malpighian  bodies  are  the  part  of 


Chap.  IV.]  Albumin.  141 

the  kidney  by  which  albumin  passes  into  the  urine. 
Tlie  causes  that  lead  to  a  transudation  of  albumin  are 
generally  referred  to  four  conditions  :  viz.,  increased 
blood  pressure,  peculiarity  of  vascular  walls,  altera- 
tions of  the  renal  epithelium,  abnormal  conditions  of 
the  blood,  though  no  one  of  these  factors  alone  seem.s 
capable  in  it.self  of  fully  accounting  for  the  phenome- 
non. In  Bright's  disease,  albumin  is  most  abundant 
in  cases  originating  in  acute  nephritis.  During  the 
early  stages  it  is  found  associated  with  more  or  less 
blood ;  as  this  clears  up,  it  still  continues  in  large 
quantity  till  the  attack  has  completely  passed  off, 
indeed,  often  persists  after  all  other  evidence  of  the 
kidney  affection  has  disappeared,  and  the  patient  has. 
apparently  regained  his  usual  health.  When  the 
acute  attack  does  not  subside,  but  merges  into  the 
chronic  form  of  nephritis  (the  large  white  kidney),  the 
albumin  passed  is  still  very  considerable.  In  the  cirr- 
hotic form  (small  granular  kidney),  the  amount  of  al- 
bumin present  in  the  urine  is  generally  small,  and 
may  be  often  absent  for  days.  Professor  Grainger 
Stewart  thinks  it  probable,  indeed,  that  cirrhosis  may 
be  present  as  an  anatomical  change,  without  the  occur- 
rence of  any  albuminuria.  Dr.  Mahomed  holds  that 
there  is  pre-albuminuric  stage  in  this  form  of  Bright's 
disease,  in  which  the  urine  for  a  time  is  free  from 
albumin.  I  have  seen  several  cases  tending  to  support 
this  view.  In  pui-e  lardaceous  disease  (waxy  kidney)  the 
quantity  passed  in  the  early  stages  is  at  first  small, 
but  increases  as  the  disease  progresses,  especially  if 
any  inflammation  of  the  tubules  intervenes.  Thus 
Professor  G.  Stewart  has  watched  it  gradually  increase 
from  a  mere  trace  till  the  daily  excretion  reached  one- 
twelfth  of  an  ounce.  The  albuminuria  associated  with 
depraved  condition  of  blood  is  generally  associated 
with  some  degree  of  nephritis ;  but  even  when  there  is 
no  positive  evidence  of  this,  we  can  readily  imagine 


142  Clinical  Chemistry.  [Chap.  iv 

how  a  toxic  agency  may  affect  the  circulation  in  the 
Malpighian  tufts  by  diminishing  the  supply  of  oxygen, 
or  lessening  the  amount  of  nutritive  material,  and  so 
allow  albumin  to  escape.  The  albumin  derived  from 
pus  cannot  be  distinguished  from  blood  serum. 
When  there  is  no  kidney  disease  the  case  can  be  dis- 
tinguished by  the  absence  of  tube  casts  ;  when,  how- 
ever, inflammatory  disease  of  the  urinary  passages 
co-exists  with  Bright's  disease,  it  is  impossible  to 
estimate  the  amount  of  albumin  derived  from  each 
cause,  and  our  opinion  with  regard  to  the  condition  of 
the  kidney  must  be  based  rather  on  a  consideration 
of  its  functional  power  as  evidenced  by  the  excretion 
of  urea,  and  the  specific  gravity  of  the  urine  after  it 
has  been  freed  from  albumin,  than  from  the  amount 
of  this  substance  present  in  the  urine.  In  cases  of 
temporary,  or  intermittent,  albuminuria,  the  urine 
passed  at  difierent  periods  of  the  day  should  be  care- 
fully examined,  and  the  examination  continued  for 
some  time,  till  the  conditions  which  lead  to  its 
production  are  fully  understood.  Even  after  all  trace 
of  albumin  has  long  disappeared  from  the  urine,  the 
patient  should  report  himself  from  time  to  time,  for 
though  in  the  majority  of  cases  no  ill  results  follow, 
still  this  condition  is  sometimes  a  prelude  to  the 
permanent  and  organic  form  of  albuminuria. 

The  best  plan  of  procedure  in  testing  for  serum 
albumin  is  as  follows  : 

(a)  First  determine  the  presence  of  a  proteid  or 
albuminous  substance  in  urine.  For  this  purpose  any 
of  the  following  reagents  may  be  used  :*  (1)  Potassium 
ferrocyanide,  with  citric  acid;  (2)  Potassio-mercuric 
iodide,  with  citric  acid ;  (3)  Mercuric  chloride,  with 

*  If  the  urine  is  turbid  from  mucus  it  must  be  filtered.  If 
the  turbidity  is  due  to  urates,  gently  warming  the  urine  will 
clear  it ;  if  due  to  phosphates,  the  addition  of  a  drop  or  two  of 
acetic  acid  will  re-dissolve  them. 


Chap.  IV.]  Tests  for  Albumin.  143 

citric  acid ;  (4)  a  saturated  solution  of  Picric  acid,  added 
in  equal  b\ilk  to  the  urine  to  be  tested  ;  (5)  Concentrated 
Nitric  acid.  The  fir.st  three  tests  can  be  conveniently 
applied  by  means  of  Dr.  Oliver's  test  papers,  which 
are  exceedingly  handy  for  clinically  testing  urine  at 
the  bedside.  In  using  these  tests  a  citric  acid  paper 
is  first  dropped  into  the  test  tube  containing  tlie  urine, 
and  then  the  special  reagent ;  if  albumin  is  present,  a 
delicate  haze  will  difiuse  through  the  fluid.  The 
picric  acid  can  be  carried  in  powder  in  a  small  box, 
and  dissolved  in  water  when  required.  It  is  an  exceed- 
ingly delicate  test  for  albumin,  very  minute  traces 
being  indicated  by  it.  It  is  also  useful  as  a  general 
urinary  test,  since  it  can  be  made  available  for  testing 
for  sugar  (Sugar,  §  119),  and  for  the  detection  of 
peptones  in  urine.  If  uric  acid  is  in  excess  it  is 
thrown  down  by  picric  acid,  and  this  precipitate  may 
be  mistaken  for  albumin  ;  it  can  be  distingixished, 
however,  by  the  fact  that  it  is  re-dissolved  on  heating, 
whereas  the  precipitate  given  with  albumin  becomes 
denser  on  tlie  application  of  heat.  Picric  acid,  too, 
has  the  advantage  of  precipitating  serum  albumin 
when  modified  by  acid,  and  also  alkali  albumin  ;  at  all 
events,  Di-.  George  Johnson,  who  has  employed  the  test 
for  many  years,  says  he  has  never  met  with  a  case  of 
highly  acid  or  alkaline  urine  in  which  a  precipitate 
did  not  occur  if  albumin  was  present.  With  nitric 
acid  a  zone  of  coagulated  albumin  is  formed  when  a 
urine  containing  albumin  is  floated  on  the  surface, 
which  is  done  by  placing  a  few  drops  of  strong  nitric 
acid  at  the  bottom  of  a  test-tube,  and  running  a  little 
of  the  urine  carefully  down  the  side  of  the  glass. 
Nitric  acid  as  a  test  has  been  almost  universally 
adopted.  It  has  the  disadvantage,  however,  of  being 
an  awkward  reagent  to  carry  about  for  bedside 
purposes,  and  is  not  quite  so  delicate  as  picric  acid. 
Like  that  body,  it  precipitates  uric  acid  when  in  excess 


144  Clinical  Chemistry.  [Chap.  iv. 

from  the  ■urine;  this  precipitation,  however,  as  in  the 
other  case,  is  distinguished  by  its  being  readily 
dissolved  by  heat. 

(b)  Secondly,  to  determine  that  the  proteid  body 
is  serum  albumin.  The  above  reactions  only  show- 
that  an  albumin  of  some  kind  or  other  is  present 
in  the  nrine,  and  not  the  variety  or  the  form. 
This  is  done  by  the  application  of  special  tests. 
Now  heat  is  the  great  distinguishing  test  for  serum 
albumin,  since  it  is  the  only  albumin  (except  sero- 
globulin,  see  page  147)  that  coagulates  at  temperature 
73°  to  75°  C.  If,  then,  after  having  determined  the 
presence  of  an  albumin  in  the  urine,  we  wish  to  decide 
that  the  body  is  serum  albumin,  we  must  heat  the  ur-ine. 
This  is  best  done  by  nearly  filling  a  test-tube  with  fil- 
tered urine,  and  applying  heat  to  near  the  boiling  point, 
when,  if  albumin  is  present,  a  deposit  varying  from  a 
faint  haze  to  a  dense  cloud  is  formed  in  the  hot 
portion  of  the  tube.  The  advantage  of  applying  heat 
this  way  is  obvious,  for  if  there  is  only  the  merest 
haze  the  difi'erence  between  the  clear  cold  and  the 
slight  turbidity  in  the  heated  portion  is  very  readily 
distinguished,  especially  if  the  tube  be  held  to  the 
light,  and  the  dark  coat-sleeve  placed  behind  the 
tube ;  whereas,  if  the  whole  of  the  urine  is  heated 
a  slight  change  may  escape  observation.  In  applying 
the  heat  test  it  must  be  remembered  {a)  that  in 
alkaline  or  slightly  acid  urine  a  cloud  of  phosphates 
may  be  precipitated  on  boiling  them  ;  they  clear  up, 
however,  on  the  addition  of  a  drop  of  dilute  acid,  or  a 
citric  acid  paper,  whilst  albumin  does  not.  If  albumin 
is  present  as  well,  both  it  and  the  phosphates  are 
thrown  down  by  heat,  whilst  the  precipitate  is  only 
partially  re-dissolved  on  adding  acid.  If  any  difiiculty 
should  occur  as  to  the  amount  of  the  partial  solution, 
a  fresh  sample  of  urine  must  be  heated  very  gently 
and  kept   for   some  time  just   below  boiling  point. 


ch.ip.  IV.)  Tests  for  Albumin.  145 

75°  to  80°  C,  when  the  albniniii  alone  coagulates;  on 
boiling  (100°  C.)  there  is  an  increase  in  the  turhirlity, 
the  phosphate  being  only  precipitated  at  the  boiling 
point.  (b)  Sliouhl  the  urine  be  alkaline,  then  the 
scrum  albumin  may  bo  modified  and  appear  as  alkali 
albumin  or  casein,  in  which  case  no  coagulation,  or 
at  the  most  only  a  slight  turbidity,  will  be  given  by 
heat,  although  the  albumin  may  be  present  in  con- 
siderable amount ;  if,  however,  we  neutralise  the 
heated  layer  with  a  drop  or  two  of  dilute  acid,  coagu- 
lation will  at  once  occur  ;  a  citric  acid  test-paper 
dipped  into  the  heated  layer  has  the  same  effect. 
{c)  Similarly,  if  the  urine  is  highly  acid,  heat  will  not 
coagulate  the  albumin,  because  it  is  converted  into 
acid  albumin  or  syntonin  ;  on  neutralising  the  urine 
with  a  droj)  or  two  of  liquor  potassie  precipitation 
at  once  occurs  ;  should,  however,  the  alkali  be  added 
in  excess,  the  precipitate  is  at  once  re-dissolved. 
The  determination  of  the  amount  of  albumin  present 
in  urine  is  often  roughly  performed  by  judging  by 
the  eye  the  amount  of  coagulated  material  deposited 
in  the  test-tube  in  relation  to  the  fluid  j  thus  it  is 
expressed  at  one-sixth  or  one-eighth,  etc.  This,  how- 
ever, is  likely  to  mislead,  unless  the  specific  gravity  of 
the  urine  is  likewise  recorded,  for  a  patient  may  be 
passing  a  considerable  quantity  of  albumin  in  a  very 
dilute  but  abundant  urine,  which  ■\\T)uld  of  course  yield 
only  a  small  volume  of  coagula,  whilst  a  scanty  but  con- 
centrated urine  would  yield  relatively  more,  though  the 
quantity  of  albumin  present  might  be  absolutely  less. 
To  make  an  accurate  estimation  the  albumin  must 
be  separated  and  weighed.  The  procedure  is  as  follows : 
Take  100  cubic  centimetres  of  urine,  place  it  in  a  glass 
beaker,  and  add  two  or  three  di'ops  of  strong  acetic 
acid,  to  render  it  slightly  acid.  Place  the  beaker  in  a 
water-bath,  100"  C,  for  about  half  an  hour,  frequently 
stirring  to  prevent  clotting,  then  set  aside  to  subside. 
K 


146  Clinical  Chemistry.  [Chap.  iv. 

When  the  coagula  have  fallen  to  the  bottom  of  the 
vessel  decant  supernatant  fluid  into  another  vessel, 
and  place  the  coagulated  material  on  a  filter  previously 
dried  and  weighed,  carefully  removing  any  portion  that 
may  adhere  to  the  glass  with  a  feather  to  the  filter. 
Set  aside  to  drain,  add  from  time  to  time  any  portion 
of  coagula  that  may  be  deposited  from  the  super- 
natant fluid  that  was  decanted.  When  every  visible 
fragment  of  coagula  has  been  transferred  to  the  filter, 
place  it  in  the  hot-air  bath  and  cautiously  dry ; 
beware  of  applying  heat  too  urgently  at  first,  or  it 
will  dry  lumpy,  and  consequently  take  longer  to  get 
rid  of  all  the  moisture,  since  the  outer  surface  will 
cake  hard  and  so  prevent  the  moisture  from  the 
interior  evaporating.  When  it  has  been  in  the  air- 
bath  some  hours  withdraw,  cool,  and  weigh,*  and 
repeat  this  process  till  it  ceases  to  lose  weight. 
When  it  does,  deduct  the  original  weight  of  the  filter 
from  the  amount,  and  the  difference  will  give  the 
weight  of  albumin  in  100  cubic  centimetres  of  urine. 
{l^.B. — This  process  answers  very  well  in  ordinary 
cases,  but  if  the  urine  is  scanty,  and  the  albumin 
is  abundant,  it  is  necessary  to  dilute  the  urine  with 
twice  its  volume  of  water,  otherwise  the  albumin  will 
separate  in  clots,  and  carry  down  some  of  the  urinary 
material,  which  of  course  will  increase  the  weight.) 

(2)  Paraglobulin  and  globulin. — These  varieties 
of  albumin,  associated  with  serum  albumin,  are  met 
with  in  many  cases  of  Bright's  disease,  chiefly  in  the 
early  acute  stage,  when  blood  appears  in  the  urine, 
and  the  later  stages  of  chronic  white  kidney,  when 
there  is  much  anaemia.  The  globulins  coagulate  by 
heat,  so  that  to  separate  them  from  serum  albumin  it 

*  In  weighing  precipitates  a  small  beaker  half-full  of  strong 
sulphuric  acid  should  always  be  placed  in  the  case  of  the 
weighing  machine,  to  keep  the  air  of  the  chamber  dry,  otherwise 
moisture  will  be  absorbed  and  weight  increased.  The  filter  should 
always  be  allowed  to  cool  in  this  chamber. 


Chap.  IV.)  Peptones  in  Urine.  147 

is  neces.sary  to  employ  a  reagent  that  does  not  aflect 
that  body.  This  is  effected  by  precipitating  with 
magnesium  sulphate ;  the  filtrate  is  heated  to  75'^  C, 
which  throws  down  the  sero-albumin,  by  passing  a 
stream  of  carbonic  acid  through  the  ui-ine,  which 
should  be  diluted  three  or  four  times  its  bulk  with 
distilled  water.  I  am  not  aware  that  the  globulins 
ever  appear  in  ui-ine  unless  accompanied  with  serum 
albumin ;  the  conditions  under  which  both  pass  out 
of  the  kidney  seem  to  be  identical,  though  in  some 
forms  of  temporary  albuminuria  paraglobulin  appears 
to  be  in  excess  of  the  serum  albumin. 

(3)  Fibrin  is  met  with  in  urine,  associated  with 
chylous  urine,  from  which  it  separates  as  a  light 
gelatinous  clot.  It  is  known  by  its  power  of  decom- 
posing hydrogen  peroxide.  After  htematuria  moulds 
of  the  urinary  tubes,  consisting  of  decolorised  fibrin 
and  fatty  matter,  are  sometimes  passed,  they  also 
cause  efi'ervescence  with  hydi'ogen  peroxide. 

(4)  Parapeptone,  or  pi-o-peptone,  sometimes  appears 
in  urina  This  body  is  one  of  the  intermediate 
products  of  gastric  and  pancreatic  digestion.  Before 
peptone  is  arrived  at,  according  to  Kiihne,  anti- 
albumose  and  hemi-albumose  are  formed.  Of  these, 
anti-albumose  corresponds  to  acid  albumin  or  syntonin, 
whilst  hemi-albumose  is  probably  equivalent  to  the 
so-called  c  peptone  of  Meissner,  which  has  been 
identified  with  the  peculiar  form  of  albumin  discovered 
by  Bence  Jones  in  the  urine  of  a  case  of  osteo- 
malacia. This  body  gives  a  precipitate  with  nitric 
acid  or  picric  acid  in  the  cold,  but  which  re-dissolves 
when  heated  to  70°  C. ;  this  form  of  albumin  is 
frequently  associated  with  the  presence  of  true 
peptone  in  the  urine. 

(5)  Peptones. — It  has  long  been  known  that  these 
bodies  often  make  their  appearance  in  urine,  but 
the   subject   has    not   received    in    this    country    the 


■148  Clinical  Chemistry.  [Chap.  iv. 

attention  it  deserves.  Frerichs,  Schultzen,  and 
Riess  have  met  with  them  in  the  urine  of 
cases  of  acute  yellow  atrophy  and  phosphorus 
poisoning  ;  Eichwald  in  acute  parenchymatous 
nephritis  ;  Petri  found  them  in  twenty-eight  cases  out 
of  forty-one  cases  tested  ;  Gerhardt  found  them  in  the 
urine  of  patients  suffering  from  diphtheria,  tertiary 
syphilis,  pneumonia,  typhus,  and  typhoid  fever;  in 
some  of  his  cases  they  preceded  the  coming-on  of 
albumin  in  the  urine.  Gerhardt's  observations  have 
been  confirmed  by  Obermiiller.  I  have  recorded* 
three  cases,  in  one  of  which  there  was  slight  temporary 
albuminuria,  and  in  two,  though  there  was  no  albu- 
min, the  patients  presented  the  appearance,  and  had 
many  of  the  symptoms,  that  would  lead  one  to  expect 
granular  or  contracted  kidney.  The  test  for  their 
presence  is  the  peculiar  rosy  red  they  give  with  alka- 
line solutions  of  cupric  sulphate  in  the  cold.  To 
bring  this  out  clearly,  place  about  a  drachm  of 
Fehling's  solution  in  the  bottom  of  a  test-tube,  and 
float  an  equal  quantity  of  urine  on  the  surface  ; 
where  the  two  fluids  meet  a  zone  of  phosphates  will  be 
deposited,  above  which,  if  peptones  are  present,  a  red 
halo  will  develop.  If  peptones  alone  are  present, 
then  the  red  is  of  a  rosy  or  pink  tint.  If  there  is 
also  much  albumin,  then  the  red  is  more  of  a  violet 
hue.  Now  if,  by  means  of  a  pipette,  a  drop  or  two  of 
picric  acid  is  allowed  to  fall  in,  the  red  coloration 
turns  to  deep-red,  then  to  reddish-yellow,  and  finally 
becomes  yellow.  It  is  a  difficult  matter  to  obtain 
these  bodies  for  examination.  The  plan  that  has 
been  usually  adopted  has  been  to  precipitate  them 
with  alcohol.  Now  albuminous  peptones  are  not 
quite  insoluble  in  alcohol,  whilst  mucin  is  freely 
precipitated  by  it;  so  that,  unless  mucin  be  previously 
removed,  this  substance  may  be  mistaken  for  peptone. 
*  British  Med.  Journal,  May  12th,  1883. 


Chap.  IV.)  Peptones  in  Urine.  149 

Again,  if  tlie  urine  contain  albumin,  it  is  very  difli- 
cult  to  separate  it  completely,  a  small  quantity  always 
remaining  even  after  repeated  coagulation  by  heat. 
The  process  I  liave  devised  is  a  modification  of  that 
adopted  by  Schultzen,  Eiess,  and  Hofmeistex-.  It  is 
as  follows  : — 500  cubic  centimetres  of  filtered  urine  are 
to  be  placed  in  a  glass  vessel,  and  10  cubic  centimetres 
of  strong  acetic  acid  added.  If  mucin  is  present  in 
solution  a  turbidity  ensues.  The  urine  is  allowed  to 
stand  twelve  hours,  by  which  time  the  precipitated 
mucin  falls  to  the  bottom  of  the  vessel.  A  drop  of 
acetic  acid  should  then  be  added  to  the  supernatant 
fluid  to  see  if  all  the  mucin  has  been  thrown  down  ; 
if  this  di'op  causes  a  cloudiness  when  it  is  allowed 
to  fall,  then  more  acetic  acid  (5  cc.)  must  be 
added,  and  the  precipitate  allowed  to  collect;  and 
this  process  must  be  repeated  till  acetic  acid  causes  no 
cloudiness  when  added.  The  clear  supernatant  fluid 
is  then  to  be  decanted  off  and  filtered.  To  this  add, 
drop  by  drop,  a  concentrated  solution  of  ferric 
chloride,  till  the  solution  has  acquired  a  permanent 
red  colour.  Then  carefully  neutralise  the  solution 
Avith  a  concentrated  solution  of  sodium  carbonate. 
Allow  the  precipitate  to  subside  ;  then  pour  off  the 
supernatant  fluid  and  filter  it.  The  filtrate  ought  now 
to  be  free  from  albumin,  and  give  no  reaction  with 
potassium  ferrocyanide  and  acetic  acid.  The  filtrate 
is  now  to  )je  evaporated  to  half  its  bulk,  and  250 
cubic  centimetres  of  absolute  alcohol  added  whilst  the 
liquid  is  yet  warm.  If  peptones  are  present,  a 
brownish  precipitate  is  the  result.  The  whole  should 
be  kept  in  the  water-bath  (100°  C.)  for  twenty- four 
hours,  alcohol  being  added  from  time  to  time.  When 
a  precipitate  is  no  longer  formed,  the  brown  substance 
must  be  removed  to  another  vessel,  and  boiled  with 
alcohol  for  twelve  hours.  The  precipitate  is  then 
collected,  dried,  washed  with  ether,  dissolved  in  water, 


150  Clinical  Chemistry.  [Chap.  iv. 

re-precipitated  by  alcohol,  again  collected,  dried,  and 
washed  by  ether.  At  length,  after  repeating  this 
process  three  or  four  times,  a  grey-yellowish  powder 
is  obtained,  which  is  hygroscopic,  is  easily  soluble  in 
water.  The  solution  is  neutral  in  reaction,  gives  no 
precipitate  with  potassium  ferrocyanide  and  acetic 
acid,  turns  the  plane  of  polarised  light  to  the  left. 
The  powder,  when  heated  to  180°  C,  evolves  ammonia. 
The  alcoholic  extracts,  exhausted  with  ether,  yield 
to  the  etherial  solution  a  brown,  thin  residue,  out  of 
which  thin  crystals  of  tyrosin  separate. 

119.  Sugar  (glucose). —  Healthy  human  urine 
contains,  as  has  been  proved  by  Pavy,  minute  traces 
of  glucose ;  but,  in  certain  unnatural  states  of  the 
system  associated  with  disturbance  of  the  hepatic 
function,  a  larger  amount  passes  into  the  urine,  in- 
ducing a  condition  known  either  as  glycosuria,  or  dia- 
betes, according  as  it  acquires  a  more  or  less  marked 
saccharine  reaction  and  is  temporary  or  permanent  in 
its  character.  The  nature  of  the  perversion  of  liver 
function  which  leads  to  the  increased  passage  of  sugar 
into  the  blood,  and  hence  into  the  urine,  and  the 
difference  of  degree  observable  in  the  various  forms  of 
diabetes  and  glycosuria,  are  considered  in  the  chapter 
on  the  digestiA^e  organs  (§  145). 

Various  substances  produce  a  reaction  with  glucose; 
but  the  tests  used  for  clinical  purposes  ai-e,  (1)  the 
alkaline  copper  test ;  (2)  the  yeast,  or  fermentation, 
test ;  (3)  the  indigo  carmine  test ;  (4)  the  picric  acid 
and  liquor  potassse  test ;  (5)  polarised  light. 

(1)  The  alkaline  coiJfer  test. — Alkaline  solutions 
of  glucose  possess  the  power  of  reducing  cupric  salts 
to  cuprous.  This  property  is  made  use  of  in  detect- 
ing sugar  in  urine.  The  test  solution  in  general 
use  is  that  of  Fehling.  It  is  made  by  weighing  3 4 "6 3 
grains  of  pure  crystallised  cupric  sulphate,  and  adding 
distilled  water  up  to  one  litre.    One  cubic  centimetre  of 


ciiap.  IV.)  Tests  for  Glucose.  151 

this  solution  is  (>quivalcnt  to  'OOO  <;rm.  of  sugar.  Tlio 
alkaliiif  solution  is  prej)arc(l  by  dissolving  173  gnus. 
of  pure  crystallised  sodio-potassiuni  tartrate  and  80 
grms.  of  potassium  hydrate  in  distilled  water,  and 
tilling  up  to  the  measure  of  one  litre.  The  copper 
and  alkaline  solutions  must  be  kejjt  in  separate  bottles. 
Thus  prepared,  the  test  is  available  for  quantitative 
as  well  as  qualitative  purposes.  In  testing  for 
sugar,  we  place  equal  quantities  (one  centimetre  of 
each  solution)  in  a  perfectly  clean  test-tube,  and  boil ; 
then  set  aside  for  a  few  minutes  to  see  if  the  solution 
is  in  good  condition  and  has  not  been  impaired  by 
keeping.  If  in  good  order,  it  remains  perfectly  clear 
and  retains  its  deep  blue  colour.  If  faulty,  it  becomes 
turbid  and  thick,  in  which  case  it  is  not  available. 
If,  however,  it  is  good,  run  a  drop  of  the  suspected 
urine  (which  must  be  freed  from  albumin,  if  present) 
down  the  side  of  the  tube,  and  gently  heat.  If  sugar 
is  abundant,  a  yellow  precipitate,  turning  red,  will  be 
formed.  If  no  precipitate  is  formed,  then  add  a  drop 
or  two  more  urine,  and  so  on  till  a  bulk  equal  to  the 
amount  of  test  has  been  added.  If  then  there  is  no 
precipitate,  we  may  be  sure  that  sugar  is  absent. 
When  the  sugar  is  in  extremely  minute  quantity,  the 
reduction  may  be  veiy  slight,  and,  instead  of  a  red  or 
reddish -yellow,  the  precipitate  is  greenish -yellow, 
caused  by  the  admixture  of  the  yellow  urine  and  a 
little  reduced  copper  with  the  blue  of  the  Fehling,  and 
rendered  opaque  by  the  presence  of  precipitated  phos- 
phates. On  standing,  liowever,  a  few  grains  of  cuprous 
oxide  will  deposit  at  the  bottom  of  the  tube ;  this 
distinguishes  it  from  the  greenish  coloration  caused 
by  inosite.  Other  substances,  as  uric  acid,  kreatinin, 
etc.,  found  in  the  urine  besides  sugar,  possess  when  in 
excess  the  propert}'  of  reducing  cupric  salts ;  we  must 
be  on  our  guard,  therefore,  against  taking  these  for 
sugar.     In  typical  cases  of  diabetes  or  glycosuria,  the 


152  Clinical  Chemistry.  [Chap.  iv. 

reaction  in  a  few  drops  of  urine  is  too  marked  to  lead 
one  into  error ;  but,  when  the  reduction  is  slight,  the 
question  arises  whether  it  is  caused  by  uric  acid  or 
sugar.  To  decide  this  question,  add  to  the  xirine  a 
solution  of  lead  acetate ;  filter ;  and  then  test  the 
filtrate  with  the  copper  solution.  If  it  does  not  now 
give  the  reaction,  then  the  former  reduction  was  due 
to  Liric  acid ;  if,  on  the  other  hand,  the  cuprous  oxide 
is  still  thrown  down,  we  may  be  sure  the  reduction  is 
due  to  glucose.  In  employing  the  test,  care  must  be 
taken  only  to  apply  gentle  heat,  since  nitrogenous 
matter  in  urine  in  the  presence  of  alkalies  gives  off 
ammonia,  which  holds  the  cuprous  oxide  in  solution 
and  prevents  its  deposition.  Again,  the  urine  sliould 
only  be  added  drop  by  drop,  since  excess  of  glucose  will 
hold  the  cuprous  oxide  in  solution.  The  quantitative 
estimation  of  sugar  by  means  of  Fehling's  solution  is 
performed  as  follows  :  Into  a  porcelain  basin,  capable 
of  holding  500  cubic  centimetres,  place  50  cc.  of 
distilled  water,  and  to  this  add,  carefully  measured  by 
means  of  a  pipette,  10  cc.  of  the  copper  solution 
and  10  cc.  of  the  alkaline  solution,  prepared  as 
directed  above ;  then  take  5  cc.  of  the  diabetic  urine, 
freed  from  albumin  if  present,  and  dilute  it  up  to  100 
cc.  with  distilled  water,  and  place  50  cc.  of  this  in  a 
Mohr's  burette,  reserving  the  other  50  co.  in  case  of 
accident  or  of  more  being  required  to  complete  the 
process.  Now  very  gradually  heat  the  contents  of 
the  porcelain  dish  to  just  the  boiling  point,  and  then 
run  a  few  drops  of  the  diluted  urine  from  the  burette. 
This  at  first  is  of  a  muddy  colour,  but  after  each 
addition  becomes  redder  and  redder  as  more  of  the 
copper  salt  is  reduced.  After  each  addition  the 
porcelain  dish  is  tilted  a  little,  to  see  if  the  edge  of 
the  fluid  has  become  colourless.  When  this  is  the 
case,  a  few  drops  of  the  contents  of  the  porcelain 
basin  must  be  withdrawn  by  means  of  a  pipette,  and 


Chap.  IV.)  Tests  FOK  Glucose.  153 

passed  tlu'ough  a  small  filter  into  a  tust  tube  contaiii- 
i  ing  a  small  quantity  of  potassium  ferrocyanide  solu- 
tion and  a  drop  or  two  of  acetic  acid.  If  no  brown 
coloration  is  given,  the  process  is  complete;  but,  if 
tluM-e  is,  then  more  of  the  diluted  urine  must  be  care- 
fully added  to  the  contents  of  tlio  porcelain  basin,  till 
the  ferrocyanide  solution  gives  no  reaction.  The  calcu- 
lation is  made  as  follows  :  Read  off  the  number  of 
centimetres  of  dilute  urine  used  from  the  burette  ; 
say,  for  sake  of  example,  they  amount  to  57  cubic 
centimetres.  Now,  as  tlie  urine  was  diluted  to  one- 
twentieth  of  its  volume,  57  cc.  of  diluted  urine  are 
equivalent  to  2 "85  cc.  of  the  diabetic  urine.  Again,  1 
cc.  of  the  copper  solution  is  equivalent  to  '005  granmie 
of  sugar;  and,  as  10  cc.  were  employed  for  reduc- 
tion, then  2-85  cc.  of  diabetic  urine  contained  "45 
gramme  of  sugar  ;  and,  supposing  the  patient  passed 
3750    cubic  centimetres  of  urine  in  the  twenty-four 

3750  cc.    X    -05  grm.  „^  ^c, 

iiours,  then  -^-^ ^^^ =    65"78  grammes 

of  sugar  passed  in  the  twenty-four  hours.     In  other 

words,  the   same  result  is   obtained  if  we  divide  the 

twenty-four  hours'  urine  by  the  number  of  centimetres 

of    the    dilute    urine   used   from   the   burette ;    thus 

3750 

— =—   =    65*78  grammes  of  sugar. 

(2)  The  fervientation  test. — Yeast  added  to  a 
solution  of  glucose,  and  kept  at  a  temperature  of  25" 
to  30°  C,  speedily  undergoes  vinous  fermentation;  as 
the  sugar  is  converted  into  carbonic  acid,  and  this 
passes  otf  into  the  atmosphere,  the  solution  loses  weight. 
This  fact  has  been  made  use  of  for  the  qiiantitative 
estimation  of  sugar  for  clinical  purposes.  Two  equal 
portions  of  urine  (4  ozs.)are  placed  in  two  6-oz.  medicine 
bottles,  and  in  one  is  placed  a  fragment  of  baker's 
yeast,  about  the  size  of  a  small  bean,  and  the  mouth 
lightly  plugged  with  cotton  wool.     The  two   bottles 


154  Clinical  Chemistry.  [Chap.  iv. 

are  to  be  kept  in  a  warm  place  for  twenty-four  hours. 
In  the  bottle  in  which  the  yeast  is  placed  fermentative 
action  soon  commences  and  carbonic  acid  formed, 
which  passes  off  through  the  cotton  wool.  At  the  end 
of  twenty-four  hours  the  specific  gravity  of  both 
bottles  is  taken,  and  the  difference  represents  the 
amount  of  sugar,  each  degree  of  specific  gravity  lost 
in  the  bottle  which  has  undergone  fermentation  repre- 
senting one  grain  of  sugar  in  each  ounce  of  the  twenty-. 
four  hours'  urine ;  then  if  the  patient  passed  260 
ounces  of  urine  in  the  day,  and  the  difference  in  the 
specific  gravity  amounts  to  7  degrees,  then  260  x  7  = 
1820  grains  of  sugar  passed  by  the  patient  in  twenty- 
four  hours.  If  French  measures  are  employed  instead  of 
English,  then  each  degree  of  specific  gravity  lost  repre- 
sents 0"2196  gramme  of  sugar  in  every  100  cc.  of  urine. 
(3)  Indigo  carmine  test  is  based  on  the  fact 
that  indogotine,  the  colouring  matter  of  commercial 
indigo,  when  heated  with  an  alkali  in  the  presence  of 
glucose  and  certain  carbohydrates,  is  converted  into  in- 
digo white,  and  which  is  capable  of  reconversion,  under 
the  influence  of  oxygen,  back  into  indogotine.  The 
change  is  repi-esented  in  the  following  equations : 
Indogotine  2(C8H5NO)  +  Hj  =  CigHiglSTgOg  indigo 
white.  Dr.  Oliver  has  recently  made  this  test  readily 
available  by  means  of  specially  prepared  test-paper. 
A  strip  is  placed  in  a  test-tube  and  covered  with  dis- 
tilled water,  and  heated  till  a  blue  solution  is  formed ; 
a  drop  of  diabetic  urine  is  then  introduced  and  heat 
applied,  care  being  taken  not  to  shake  the  solution 
or  allow  it  to  boil.  The  solution  gradually  becomes 
violet,  then  purplish,  then  orange-red,  then  reddish- 
yellow,  and  finally  straw-coloured.  Now  on  ceasing  to 
heat,  and  shaking  the  test-tube,  the  liquid  passes  back 
through  the  different  colours  into  the  original  blue. 
This  test  is  likely  to  prove  a  valuable  supplement  to 
the  other  tests  for  sugar.     The  copper  test,  as  is  well 


Chap.  IV.]  Tests  FOR  Glucose.  155 

known,  is  not  rednced  by  all  forms  of  sugar,  nor  do 
all  kinds  ferniont  ri.'adily  with  yeast;  now  as  tlic  indigo 
reaction  is  given  by  many  forms  of  carbohydrate, 
it  may  be  thus  made  available  for  distinguishing 
between  those  forms  of  sugar  sometimes  present  in 
urine  which  give  no  reaction  with  copper,  and  which 
do  not  readily  ferment,  and  so  help  to  distinguish  those 
cases  from  true  glycosuria. 

(4)  Picric  acid  test. — When  an  alkaline  solu- 
tion of  glucose  is  heated  with  picric  acid,  the  liquid 
assumes  a  deep  red-brown  colour,  due  to  the  formation 
of  picramic  acid.  This  alibrds  an  extremely  delicate 
test  for  glucose  in  urine,  and  it  has  also  an  additional 
advantage  for  clinical  pur2)0ses,  since  picric  acid  is 
a  delicate  test  for  albumin,  and  also  that  the  presence 
of  albumin  does  not  interfere  with  reaction  for  sugar. 
In  applying  the  test,  add  an  equal  bulk  of  saturated 
solution  of  picric  acid  to  the  urine ;  if  albumin  is  pre- 
sent a  cloudy  precipitate  will  form ;  then  add  a  few 
drops  of  liquor  potassse,  and  gently  apply  heat,  the 
solution  mil  gradually  acquire  a  deep  red-brown  colour. 
Nearly  all  urines  treated  in  this  way  become  darker  in 
colour,  but  the  coloration  in  no  way  approximates 
to  that  yielded  by  even  the  most  minute  trace  of 
sugar.  Dr.  George  Johnson,  who  has  paid  much 
attention  to  the  application  of  the  picric  acid  test  for 
clinical  purposes,  has  devised  an  exceedingly  ingenious 
method  of  quantitatively  estimating  the  amount  of 
sugar  by  the  depths  of  colour  yielded  by  this  reaction 
as  compared  with  a  standard  colour  for  comparison. 
His  method  is  likely  to  be  lai'gely  used  for  clinical 
investigations,  as  it  can  be  quickly  performed.* 

Take  a  fluid  drachm  of  a  solution  of  grape-sugar, 

in  the  proportion  of  a  grain  to  the  fluid  ounce ;  mix 

it  with  half  a  drachm  of  liquor  potasste  (F.B.),  and  ten 

minims  of  a  saturated  solution  of  picric    acid ;   and 

*  Brit.  Med.  Journal,  March,  1883. 


156  Clinical  Chemistry.  [Chap.  iv. 

make  up  the  mixture  to  four  draclims  with  distilled 
water.  The  mixture  is  conveniently  made  in  a  boiling 
tube,  ten  inches  long  and  three-fourths  of  an  inch  in 
diameter,  which  may  be  marked  below  at  the  height 
of  two  and  four  drachms.  With  a  long  boiling-tube 
there  is  little  risk  of  the  liquid  boiling  over ;  and  the 
steam,  condensing  in  the  upper  cool  part  of  the  tube, 
flows  back  as  liquid,  so  that  there  is  little  loss  by 
evaporation.  The  liquid  is  now  raised  to  the  boiling 
point,  and  the  boiling  is  continued  for  sixty  seconds 
by  the  watch,  so  as  to  insure  the  complete  reaction 
between  the  sugar  and  the  picric  acid.  During  the 
process  of  boiling,  the  pale  yellow  colour  of  the  liquid 
is  changed  to  a  beautiful  claret  red. 

The  liquid  having  been  cooled,  by  cautiously  im- 
mersing the  tube  in  cold  water,  and  it  having  been 
ascertained  that  its  level  is  that  of  the  four-drachm 
mark  on  the  tube,  or,  if  below  the  mark,  it  having 
been  brought  up  to  it  by  the  addition  of  distilled  water, 
the  colour  is  that  which  results  from  decomposition  of 
picric  acid,  by  a  grain  of  sugar  to  the  ounce,  four  times 
diluted ;  in  other  words,  it  indicates  one-fourth  of  a 
grain  of  sugar  to  the  ounce ;  and  this  colour  is  a  con- 
venient standard  for  comparison  in  making  a  volumetric 
analysis.  The  picramic  acid  solution,  however,  on 
exposure  to  light,  even  for  a  few  hours,  becomes  paler ; 
but  the  colour  may  be  exactly  imitated  by  a  solution 
of  ferric  acetate,  with  a  slight  excess  of  acetic  acid 
and  an  excess  of  ferric  chloride.  The  iron  solution  we 
have  found  to  retain  its  colour  unchanged  for  a  fort- 
night, even  when  exposed  to  a  strong  light ;  and  we 
expect  that,  when  light  is  excluded,  it  may  be  kept 
for  an  indefinite  period ;  and  it  is,  therefore,  a  conve- 
nient standard  for  comparison. 

If,  now,  a  drachm  of  a  solution  of  grape-sugar, 
containing  two  grains  to  the  ounce,  be  mixed  with  the 
same  quantity   of   liquor  potassse  (half-a-drachm)   as 


Chap.  IV.] 


Tests  for  Glucose. 


'57 


before,  but  with  double  the  amount  of  picric  acid  (i.e., 
twenty  minims),  and  made  up  to  four  drachms  in 
the  boiling  tube,  the  result  of  boiling  the  mixture  as 
before,  for  sixty  seconds,  will  be  the  production  of  a 
much  darker  colour  than  when  tlie  one-grain  solution 
was  acted  upon  ;  but  if  now  the  dark  liquid  be  'diluted 
with  its  own  volume  of  water,  the  colour  will  be  the 
same  as  that  of  the  one-grain  solution. 

The  dilution  is  accurately  done  in  a  stoppered  tube, 
twelve  inches  long  and  three-quarters  of  an  inch  in 
diameter,  graduated  into  yV  and  yj^  equal 
divisions  (Fig.  11).  By  the  side  of  this  tube, 
and  held  in  position  by  an  S  -  shaped  band 
of  metal,  is  a  stoppered  tulie  of  equal  dia- 
meter, and  about  six  inches  long,  contain- 
ing the  standard  iron  solution. 

Sufficient  of  the  dark  saccharine  liquid 
to  be  analysed  is  poured  in  to  occupy 
exactly  ten  divisions  of  the  graduated 
tube.  Distilled  water  is  then  added 
cautiously,  until  the  colour  approaches 
that  of  the  standard.  The  level  of  the 
liquid  is  then  read  off  and  noted.  A  more 
exact  comparison  of  the  saccharine  liquid 
with  the  standard  is  made  by  pouring  into 
a  flat-bottomed  colourless  tube,  about  six 
inches  long  and  an  inch  in  diameter,  as 
much  of  the  standard  as  will  form  a  column  of  liquid 
about  an  inch  in  height,  and  an  exactly  equal  column  of 
the  saccharine  liquid  in  a  precisely  similar  tube.  The 
operator  then  looks  down  through  both  tubes  at  once, 
one  being  held  in  each  hand,  upon  the  surface  of  a  white 
porcelain  slab,  or  a  piece  of  white  paper.  In  this  way 
a  slight  difference  of  tint  is  readily  recognised,  and  if 
the  liquid  to  be  analysed  be  found  to  be  darker  than  the 
standai'd,  it  is  returned  to  the  graduated  tube,  and 
diluted  until  the  two  liquids  are  found  to  be  identical  in 


Fig.  11. 


158 


Clinical  Chemistry. 


[Chap.  IV. 


colour,  when  the  final  reading  is  taken.  The  saccharine 
liquid  having  been  diluted  four  times  before  it  was 
boiled,  a  colour  eqvial  to  that  of  the  quarter-grain 
standard  would  indicate  one  grain  of  sugar  per  fluid 
ounce.  If  further  dilution  were  required  (say  from 
ten  to  twenty  divisions)  the  proportion  of  sugar  would 


rig.  12. — Polarimeter. 


be  two  grains  per  ounce,  and  so  on  to  thirty  or  forty 
or  upwards,  or  to  intermediate  divisions.  Thus  dilu- 
tion from  ten  to  thirty-five  divisions  would  indicate 
3-5  grains  of  sugar  per  ounce. 

(5)  Polarimetry. — Glucose  possesses  the  pro- 
perty of  rotating  polarised  light  toward  the  right. 
This  property  has  been  made  use  of  to  determine  the 
amount  of  sugar  present  in  solution,  by  the  amount  of 
deviation  observed.  This  is  done  by  an  instrument 
termed  a  saccharometer,  represented  at  Fig.  12.  Light 
is  admitted  through  a  Nicol's  prism  or  folariser  at  6, 
and  falls  on  another  prism,  the  analyser,  at  a.  Now 
if  these  two  prisms  are  arranged  so  that  no  light  passes 


Chap.  IV.)  Blood  in  Urine.  159 

tlirouLjh  tlie  analyser  or  sf^cnnd  prism,  which  is  rlono 
by  turning  it  round  to  a  certain  d(!groe  ])y  means  of 
screw  d.  Tlie  instrument  lieing  so  adjusted  that  no 
light  passes  through  tlie  second  prism,  the  tube  c  c  is 
then  tilled  with  a  solution  of  glucose,  and  placed  be- 
tween the  two  prisms  a  and  h.  Immediately  light 
passes  again  through  the  second  prism  a,  and  this 
must  be  turned  by  means  of  d  through  a  certain 
angle  till  the  light  can  again  be  stopped.  The  mag- 
nitude of  this  angle  is  read  off  on  scale  e.  Now  the 
magnitude  is  in  direct  proportion  to  the  length  of  the 
tube  and  the  quantity  of  sugar  in  solution.  If,  there- 
fore, we  know  the  specific  rotatory  power  of  the 
substance  submitted  for  analysis  [ajn,  which  in  the 
case  of  glucose  is  -f  57 "G,  and  have  ascertained  the 
length  of  the  tube  I,  and  the  magnitude  of  the  angle 

a 

of  deviation,  then-p-] 1  =  ^,  ^^  weight  in  grammes 

[a  J  I)  X  t 

of  the  substance  present  in  1  cc.  of  the  solution  em- 
ployed. In  examining  diabetic  urine  (freed  from 
albumin,  if  present),  10  cc.  of  solution  of  lead  acetate 
are  added  to  100  cc.  of  the  urine,  in  order  to  remove 
the  colouring  matter  of  the  urine,  and  the  solution 
filtered ;  the  liquid  is  then  placed  in  tube,  the  length 
I  of  which,  in  decimeters,  has  been  ascertained,  and  the 

a 
ancfle  of  deviation  a  read  off,  then  vz-7; — -,  =  x  grms. 

[«]d 
of  glucose  in  each  cc.  of  urine. 

120.  Blood  appears  in  the  urine  under  a  variety 
of  conditions,  (a)  It  may  come  from  any  part  of  the 
genito-urinaiy  tract,  the  result  of  local  disease  or 
injuiy,  as  in  acute  nephritis,  calculous  disease,  para- 
sites, cancer,  tubercule,  etc.  ;  (6)  or  it  may  result  from 
certain  depraved  conditions  of  the  blood  itself,  as  in 
scurvy,  purpui-a,  and  the  ha^maturia  that  often  attends 
eruptive  and  continued  fevers  of  malignant  type  ;  (c) 


i6o  Clinical  Chemistry.  [Chap.  iv. 

or  from  simple  passive  congestion,  such  as  occurs  in  the 
obstructive  forms  of  heart  disease;  ((^)  from  tempo 
rary  disturbance  of  the  renal  circulation,  as  in  inter 
raittent  fever,  or  from  mental  emotion,  and  the  like. 
The  quantity  of  blood  passed  into  the  urine  is  very 
variable.  It  may  be  so  small  as  only  to  give  a  smoki- 
ness  to  the  urine,  or  so  great  as  to  colour  the  urine 
deep  red,  and  to  separate  into  large  coagula  in  the 
urinary  passages.  It  must  be  remembered,  however, 
that  a  very  little  blood  is  capable  of  giving  a  very  deep 
coloration  to  urine.  In  some  experiments  I  made  in 
1873,  at  the  laboratory  of  Charing  Cross  Hospital,  and 
published  in  the  Lancet,  I  found  that  only  one  part  of 
blood  gave  a  decided  smoky  tint  to  1500  parts  of  normal 
urine,  whilst  1  part  in  500  gave  a  bright  cherry  colour. 
Considerable  haemorrhages,  therefore,  are  best  judged  by 
the  amount  of  coagula  rather  than  by  mere  intensity  of 
colour.  When  blood  appears  in  urine  and  the  blood 
corpuscles  are  recognised  under  the  microscope,  the 
condition  is  termed  hsematuria ;  when  no  corpuscles 
are  to  be  found,  but  only  the  colouring  matter,  then 
it  is  spoken  of  as  hsematinuria. 

(1)  Haematuria. — The  character  of  the  haemorr- 
hage, together  with  the  general  and  special  symptoms,  is 
usually  sufficient  to  indicate  the  part  of  the  genito- 
urinary tract  from  whence  it  is  derived,  thus  : — 

(a)  Acute  Nephritis. — Smoky  to  dark  brown  urine 
persistent  for  some  days,  with  granular  and  blood 
casts,  and  excess  of  albumin. 

(h)  Renal  calculus. — Often  deep  red  from  excess 
of  blood,  increased  by  movement,  and  passing  off 
rapidly  if  the  patient  is  kept  quiet  in  bed,  so  that 
only  a  few  blood  corpuscles  can  be  seen  in  the  urine. 
Generally  accompanied  or  immediately  following  a 
severe  attack  of  colic  ;  retraction  of  testicle  on  side 
affected.  Vesical  calculus  :  haemorrhage  generally 
follows  undue  movement,  especially  jolting ;  bladder 


Chap.  IV.]  Blood  in  Urine.  161 

symptoms,  prominent;  deti'ction  of  .stone  in  bladder  by 
sound. 

(c)  Cancer  of  kidney. — Htematuria  very  abundant, 
with  large  coagula,  and  rej^eated  at  irregular  intervals, 
generally  tumour  in  loin.  Cancer  of  bladder,  frequent 
and  profuse  litemorrliago,  cancer  cells  in  urine,  pain 
referable  to  bladder,  and  a  tumour  may  be  discovered 
"with  sound. 

{d)  Morbid  conditions  of  the  blood. — Hsemon-hage 
often  ])rofuse,  but  rai'cly  attended  with  formation  of 
clot.      General  constitutional  symptonis  manifest. 

(e)  Intermittent  ha-maturia. — The  blood  passes  at 
very  irregular  inter\als,  is  generally  associated  with  a 
considerable  quantity  of  albumin  and  a  definite  rise 
of  temperature.  In  these  cases  there  is  usually  a 
history  of  ague,  if  the  disease  is  not  actually  in 
progress  ;  it  is  sometimes  associated  with  intermittent 
chylui'ia  or  gout. 

(2)  Hamatinuria.  —  In  these  cases  only  the 
colouring  matter  of  the  blood  is  present,  no  blood 
corpuscles,  or  only  a  few,  are  to  be  found.  The 
attacks  come  on  in  paroxysms,  attended  Avith  a  chill, 
and  genei'ally  accompanied  Avith  some  degree  of  nausea 
and  slight  jaundice.  The  urine  has  a  port-wine 
colour,  and  is  usually  passed  clear.  On  standing 
it  deposits  a  granular  sediment,  consisting  of  a  few 
tube  casts  and  fibrinous  cylinders,  epithelium,  crystals 
of  calcium  oxalate,  in  some  cases  crystals  of  htematin 
have  been  observed.  From  the  fact  that  the  spectrum 
of  this  kind  of  urine  invariably  shows  the  charac- 
teristic bands  of  htemoglobulin,  many  writers  desig- 
nate the  disease  hsemogiobiuuria.  But  in  addition, 
however,  to  the  bands  in  D  and  E  characteristic  of 
hsemoglobulin,  there  is  invariably  a  third  present  near 
c,  Avhich  corresponds  with  that  given  by  methsemo- 
globin  in  acid  solutions.  {See  Fig.  4,  §  95.)  Formerly 
metluemoglobinwas  supposed  to  be  per-oxy-htemoglobin, 

L 


1 62  Clinical  Chemistry.  [Chap.  iv. 

in  whicli  case  by  reduction  methsemoglobin  ought 
to  yield  oxy-Ksemoglobin,  but  it  yields,  however,  re- 
duced hsemogiobin.  This  and  other  considerations 
make  it  probable  that  methsemogiobin,  instead  of  con- 
taining more  oxygen,  actually  contains  less  than  oxy- 
hsemogiobin,  and  that  as  regards  iron,  whilst  this 
body  is  at  its  minimum  in  oxy-hsemoglobin,  it  is  at  its 
maximum  in  methsemogiobin.  These  considerations, 
therefore,  make  it  probable  that  the  oxy-hsemoglobin 
is  undergoing  a  downwai'd  change  into  hsematin. 
The  pathology  of  the  disease  is  still  obscure,  though 
the  iuteresting  researches  of  Jaffe  and  MacMunn 
on  the  origin  of  the  urinary  pigments  seem  to 
throw  some  light  on  it  If  the  effete  hsemogiobin 
is  converted  in  the  liver  into  hsematin  and  then  into 
bile  pigments,  one  of  which,  urobilin,  is  oxydised 
into  choletelin,  which  appears  in  the  uiine ;  and  if 
this  conversion  does  not  always  take  place,  it  may 
be  owing  to  some  functional  disturbance  of  the 
liver,  the  effete  hsemogiobin  may  escape  conversion 
in  the  liver,  and  be  eliminated  by  the  kidney,  as 
hsemogiobin  undergoing  the  downward  change  into 
hsematin  before  conversion  into  choletelia  (§  100). 
That  there  is  some  disturbance  of  hepatic  function 
is  indicated  by  the  jaundice  attendant  on  this  con- 
dition. 

The  tests  for  blood  in  urine.  When  due  to  hsema- 
turia,  the  detection  of  blood  corpuscles  by  the  micro- 
scope affords  the  best  and  most  positive  indication  of 
the  presence  of  blood.  These,  however,  vary  in 
shape.  If  the  urine  is  moderately  acid  they  retain 
their  natural  form  a  considerable  time,  but  they 
become  jagged  at  their  edges,  lose  colour,  and  no 
longer  adhere  together.  If  the  blood  corpuscles 
become  dissolved,  then  we  may  try  Heller's  hsematin 
test,  which  consists  in  boiling  the  urine  with  a 
concentrated    solution   of    caustic    potash,  when   the 


Chap.  IV.]  Bile  in  Urine.  163 

phosphatps  carry  down  the  liaMuatin  as  a  rofldish- 
brown  pr(>ci|iitate,  wliich  by  tran.smitted  liglit  ha.s  a 
greenish  tint  ;  and  wliieh  precij>itate,  treated  with 
.sodium  cidoride  and  acetic  acid,  yields  crystals 
of  hiemin  (Fig.  3,  §  95).  The  guiacum  test  is 
best  applied  by  filling  a  test-tube  one-third  with 
tincture  of  guiacum  and  adding  a  few  drops  of  the 
suspected  urine,  then  float  about  a  di'achm  of  etherial 
solution  of  peroxide  of  hydrogen  on  the  surface,  and 
at  the  line  of  junction,  if  blood  is  present,  a  delicate 
blue  colour  is  developed.  This  test,  however,  is  not 
to  be  depended  on,  except  as  a  general  one,  since  often 
extraneous  substances  besides  blood  may  give  the 
reaction  in  urine.  If  any  doubt  exists,  the  spectro- 
scopic examination  will  reveal  characteristic  bands  of 
oxy-hajmoglobin,  reduced  haemoglobin,  meth?emoglobin, 
or  h;ematin,  according  to  circumstances,  and  the 
degree  of  decomposition  that  has  occurred. 

121.  Bile.  —  The  conditions  which  lead  to  the 
appearance  of  bile  in  the  urine  are  discussed  in 
chapter  v.,  §  138.  Urine  containing  bile  varies  from  a 
deep  brownish-red  to  the  colour  of  London  porter. 
A  linen  rag  dipped  in  it  acquires  a  yellow  stain. 
This  coloration  is  due  to  bile  pigment.  The  reaction 
for  this  is  readily  shown  by  placing  on  a  white 
plate  or  dish  a  few  drops  of  the  urine,  and 
near  it  a  few  drops  of  nitric  acid  to  which 
one  drop  of  suli)hui'ic  acid  has  been  added  (to  form 
free  nitrons  acid),  and  then  allow  the  two  fluids  to 
mix.  If  bile  pigment  is  present,  a  play  of  colour  is 
observable,  of  which  the  green  tint  is  characteristic  of 
bile  pigment  {Gmelin's  test).  Bile  acids  are  present, 
as  well,  in  the  urine  of  some  cases  of  jaundice. 
They  are  detected  by  adding  a  few  grains  of  glucose 
to  the  urine,  and  then  allowing  the  solution  to  run 
down  the  side  of  a  test  in  which  a  little  concen- 
trated   sulphuric    acid    has   been    placed ;    a   purple 


164  Clinical  Chemistry.  [Chap.  iv. 

reaction  {Pettenhoffer'' s  test)  will  develop  if  they  are 
present.  As  some  other  substances  give  this  reaction, 
if  there  is  any  doubt  the  bile  acids  must  be  separated 
from  the  urine  by  evaporating  it  to  a  thick  syrup, 
extracting  with  ordinary  alcohol,  evaporating  the 
alcoholic  solution,  and  treating  the  residue  with 
absolute  alcohol.  Evaporate  this  solution,  and  dissolve 
the  residue  in  distilled  water,  and  precipitate  the 
solution  with  neutral  and  basic  lead  acetate.  The 
precipitate  is  dissolved  in  water,  and  decomposed  with 
hydrogen  sulphide,  and  filtered.  The  filtrate  is 
treated  with  excess  of  sodium  carbonate,  and  concen- 
trated. On  standing,  long  needle-like  crystals  of 
glycocholate  of  soda  will  form,  with  oily  globules  of 
taurocholate  of  soda. 

122.  Chylous  urine. — In  the  disease  known  as 
chyluria  the  urine  has  a  milky  appearance,  sometimes 
slightly  tinged  with  blood,  and  yields  a  delicate 
fibrinous  clot.  On  standing  this  clot  comes  to  the 
surface  of  the  urine,  and  forms  a  distinct,  jelly-like 
layer.  This  clot  possesses  the  property  of  fibrin,  of 
decomposing  peroxide  of  hydrogen.  Besides  the 
addition  of  this  abnornial  ma,tter,  the  urine  is  little 
altered  in  its  other  characters.  After  the  separa- 
tion of  the  clot,  the  blood,  the  extraneous  albumin, 
and  the  removal  of  the  fatty  matter  by  extraction 
with  ether,  I  h^ve  found  the  urea  normal  in  propor- 
tion, though  the  amount  of  water  is  relatively 
increased.  The  chylous  matter  is  apparently  derived 
from  the  lymphatics,  probably  due  to  some  lesion  of 
those  connected  with  the  kidney.  The  disease  is 
sometimes  ]Dersistent,  but  frequently  it  is  occasional 
and  intermittent,  There  are  cases  on  record  in 
which  the  urine  was  observed  milky  on  a  few  occasions 
only,  but  never  afterwards  made  its  appearance.  The 
most  completely  recorded  case  of  typical  persistent 
chyluria,   associated  with  filaria  in  the  blood,  is  by 


Ch.np.  I  V.J 


CUVLURIA, 


I  ^^5 


Dr.  Stephen  Mackenzie*  Bricgoif  has  giveti  some 
very  ('nm]il('tp  aiialysos  of  the  night  urine;  two,  the 
m.'ixiiiiiuii  aiul  iiiiiiiimiin,  arc  hero  appended  : 


Maximum 

in 
100  piirts. 

Minimum 

in 
100  parts. 

Fats. 

Albumins ..... 

Urea 

Uric  acid 

Sodium  chloride 

Sulphates           .... 

0-725 

0.798 

3-4 

0-03 

1-7 

0-22 

006 

0-681 

3-7 

0-03 

1-4 

0-23 

Quantity  of  urine     , 
Specific  gravity 

400cc. 
1-OlGcc. 

300cc. 
1-025CC. 

Both  urines  contained  peptones  and  traces  of  indican. 
The  fatty  matters  consisted  of  ordinary  fatty  matter, 
lecithin,  and  cholesterin.  To  examine  a  chylous 
urine,  filter  off  the  coagulum,  and  exhaust  it  thoroughly 
with  ether,  water,  and  alcohol  till  quite  free  from  fat 
and  albumin;  dry  and  weigh.  Agitate  the  ui'ine 
with  successive  quantities  of  ether  till  no  more  fat 
is  taken  up.  Evaporate  the  etherial  solution  in  a 
weighed  platinum  capsule,  weigh  the  dried  residue, 
which  gives  amount  of  fatty  matten  (For  separate 
determination  of  the  nature  of  these  fatty  matters 
see  §  99.)  The  urine  freed  from  fatty  matters  can 
then  be  examined  quantitatively  for  albumin  (§  118), 
peptones  (§  118,  ISTo.  5),  urea  (§  110),  uric  acid 
(§  111),  chlorides  (§  114),  sulphates  (§  115),  phos- 
phates (§  113). 

Apart  from   chyluria  the   urine  often  assumes  a 
milky  appearaiace,  from  the  presence  of  fatty  matters 

*  Path.  Soc.  Trans.,  vol.  xxxiii.,  p.  394. 
t  Zeitsch.  Phys.  Chemie,  p.  411,  1880, 


1 66  Clinical  Chemistry.  [Chap.  iv. 

in  a  state  of  extremely  fine  subdivision ;  the  urine 
in  these  cases  is  generally  slightly  albuminous,  and 
often  gives  the  peptone  reaction  with  cupric  sulphate. 
In  Bright's  disease,  fatty  matters  may  appear  in 
the  urine,  apparently  derived  from  the  degenerated 
epithelium  of  the  tubules.  I  have  met  with  a  small 
quantity  of  fatty  matter  in  the  urine  of  a  patient  dying 
of  acute  diabetic  coma.  Plates  of  cholesterin  are 
sometimes  met  with  as  a  urinary  deposit. 

123.  Cystin  CsH^NSO^. —According  to  Dr. 
Bence^  Jones,  cystin  is  constantly  being  separated  in 
the  healthy  organism,  immediately  undergoing  trans- 
formation into  sulphuric  acid,  carbonic  acid,  and 
urea.  Whenever  this  chemical  transformation  is 
arrested  cystin  appears  in  the  urine.  As  the  com- 
position of  cystin  is  C3H.NSO2,  the  proportion  of 
nitrogen  to  carbon  is  four  to  twelve ;  in  uric  acid 
C5H4N4O3  it  is  four  to  five  ;  and  in  urea  CH4NaO  four 
to  two  :  therefore  twelve,  five,  and  two  are  the  indices 
representing  the  different  amounts 
of  suboxydation  in  cystin,  uric  acid, 
and  urea  respectively.  Dr.  Bence 
Jones  thus  regards  cystin  as  repre- 
senting the  smallest  degree  of  the 
oxydation  of  the  albuminous  prin- 
ciples, in  the  same  way  that  sugar 
in  diabetes  represents  the  least 
degree  of  oxydation  of  the  amyla- 
^^'Crystais,^*"^  ceous  principles.  Cystin,  however, 
as  a  urinary  deposit  is  extremely 
rare.  When  it  appears  it  forms  a  whitish  or  faAvn- 
coloured  sediment,  which  is  dissolved  by  ammonia, 
and  from  which  on  evaporation  it  is  deposited  va, 
hexagonal  plates  (Fig.  13),  and  which  are  insoluble 
in  acetic  acid.  Heated  in  a  solution  of  lead  ace- 
tate, a  precipitate  of  lead  sulphide  is  formed,  owing 
to  the  sulphur  contained  in  cystin.     The  pathological 


Chap.  IV.]  XaNTIIIN.  1 67 

significance  of  cystin  in  uriiu^  is  not  yet  determined. 
I  Imve  met  witli  it  in  the  urine?  of  strumous  chil- 
dren, and  in  adults  su(l"orinijf  from  di.sea.se  of  the  liver. 
It  sometimes  is  retained  in  the  urinary  passages  and 
forms  a  calculus. 

12-1.  Xaiilhiii  C-JI  ,N|0o  is  a  constituent  of  certain 
rare  urinary  cak;uli,  antl  Dr.  Bence  Jones  has  re- 
corded an  interesting  ca.se  of  xanthin  gravel  in  a  boy 
aged  nine  years.  The  xanthin  calculus  removed  by 
Langenbeck  was  also  from  a  boy.  Dr.  Bence  Jones 
considers  that  the  xanthin  diathesis  will  be  generally 
found  to  occur  in  youth,  as  it  is  in  the  early  period  of 
life  the  greatest  chemical  variations  of  the  body  are 
to  be  expected,  and  the  most  imperfect  oxydation  of 
xanthin  into  uric  acid  most  likely  to  occur.  To 
separate  it  from  urine,  add  baryta  water  till  a  preci- 
j)itate  is  no  longer  thrown  down;  filter,  and  evaporate 
the  filtrate  to  a  syrup,  and  allow  it  to  crystallise. 
The  mother  liquor,  after  the  removal  of  the  crystals, 
is  boiled  with  cupric  acetate,  and  the  precipitate  thus 
formed  is  removed  by  filtration, 
washed,  and  dissolved  in  warm  nitric  J\^() 

acid.       This  acid  solution  is  precipi-  k^^  Iv^  A 

tated  by  silver  nitrate,  and  the  result-        \^^ ^^(1  a 
ing  precipitate  washed   and   crystal-     ^^^^^^  t^ 
lised  from  dilute  nitric  acid,  and  the      f)^f\^^%^^ 
crystals    washed    with    ammoniacal    ^V'|t')  (/\l   /^ 
silver     solution,    and    suspended    in     v)    \)  /)     r^ 

water.      The  aqueous  solution  is  to  (j  .^^  \ I 

be  decomposed  with  snlphydric  acid,      ^v^^  n     ^^    & 
filtered,     and     the     filtrate     evapo-         /^  \\  y7 
rated  ;    the   residue    yields  xanthin.  \} 

Xanthin    forms   white  scales,  some-      „.    , ,     „    , , . 

.  .      '  FiL'.  14-. — AnutuiJi 

what  resembling  beeswax  m  appeal'-         '  Crystals, 
ance.     Deposited  spontaneously  from 
urine  it  occurs  in  lemon-shaped  plates    (Fig.  14,  a)\ 
these,  dissolved  in  hydrochloric  acid  and  the  solution 


1 68  Clinical  Chemistry.  [CUap.  iv. 

evaporated,  yield  prismatic  and  hexagonal  crystals  (6). 
Xanthin  is  insoluble  in  water,  alcohol,  and  ether; 
soluble  in  alkaline  solutions,  from  which  it  is  deposited 
by  a  current  of  carbonic  acid  gas ;  and  in  strong 
mineral  acids.  Burnt  in  air,  it  gives  off  the  odour 
of  scorched  hair.  Evaporated  with  nitric  acid  on 
platinum  foil,  and  the  residue  moistened  with  liquor 
potassse,  it  yields  a  dark  purple  colour.  Xanthin 
gives  white  precipitates,  with  mercuric  chloride  and 
silver  nitrate.  Dissolved  in  hydrochloric  acid,  it  gives 
with  platinic  chloride  a  yellow  crystalline  precipitate. 

125.  Hypoxanthin  CgH4]S'40  has  been  found 
in  the  urine  of  patients  suffering  from  leucaemia;  to 
separate  it,  add  baryta  water  and  filter  off  the  pre- 
cipitate. To  the  filtrate  ammoniacal  solution  of 
silver  nitrate  is  added,  and  the  greyish- white  precipi- 
tate collected  on  a  filter  and  washed.  The  precipitate 
is  then  to  be  suspended  in  water,  decomposed  with 
sulphydric  acid,  the  mixture  boiled  for  some  time, 
and  filtered  while  hot.  The  filtrate  is  next  evapo- 
rated to  dryness,  the  residue  contains  uric  acid, 
xanthin,  and  hypoxanthin.  To  separate  the  uric  acid 
and  xanthin,  the  residue  is  to  be  dissolved  in  dilute 
sulphuric  acid,  boiled,  and  filtered  whilst  hot ;  to  the 
filtrate,  when  cold,  mercuric  nitrate  is  added  and 
filtered.  To  the  filti'ate  some  ammoniacal  solution  of 
silver  nitrate  is  added ;  the  precipitate  consists  of 
hypoxanthin  nitrate  and  silver  oxide.  This  is  decom- 
posed with  sulphydric  acid  and  hypoxanthin  is  preci- 
pitated as  a  white,  imperfectly  crystalline  powder, 
rather  more  soluble  in  water  and  alcohol  than  xanthin. 
It  dissolves  freely  in  acids. 

126.  lieucin  CgHigNOg  has  generally  been  met 
with  in  the  urine  in  cases  of  acute  yellow  atrophy 
of,  the  liver,  in  cirrhosis  of  that  organ,  and  in  severe 
cases  of  small-pox  and  typhus.  Dr.  Anderson,  how- 
ever, has  found  leucin  somewhat  frequently  in  urine 


Chap.  IV.]  LEUCItf.  i6g 

uudor  less  severe  conditions.  He  believes  that  both 
leucin  and  tyrosin  are  found  in  the  urine  under  numer- 
ous diirereut  pathological  conditions,  whether  affecting 
the  liver  intrinsically,  or  from  without ;  and  that  as 
often,  or  as  soon  as  the  jiatient  recovers,  these  substi- 
tution products  for  urea  Hrst  diminish  in  amount  and 
then  disajipear  (^Med.-Chir.  Soc.  Trans.,  vol.  Ixiii., 
p.  245).  Without  entirely  agreeing  with  all  the 
author's  conclusions,  I  believe  we  should  find  leucin 
more  frequently  if  we  looked  for  it.  Leucin,  as  well 
as  tyrosin,  has  an  interest  in  consequence  of  its 
formation  dui-ing  pancreatic  digestion.  When  present 
in  urine,  it  is  only  required  to  evaporate  about 
five  ounces  of  that  fluid  to  a  thin  syrup,  and,  when 
cold,  leucin  in  the  shape  of  oily  cii'cular-looking  discs 
will  be  deposited. 

Leucin    obtained    from    urine  is  not    crystalline, 
but  forms  circular  oily-looking  discs  (Fig.  L5,  a)  which 
float    on    the    surface   of    water ; 
they  generally   have  a  somewhat 
yellowish    appearance,    owing  to 
the  colouring  matter  of  the  urine. 
If  this  form  of  leucin  be  dissolved 
in  boiling  alcohol,  the  solution  on 
cooling    will    deposit    leucin    in       j,jg_  jg  _„^  Lencin; 
crystalline  plates.     Leucin  is  de-  b.  Tyrosin. 

posited  from  its  alcoholic  solution 

in  white  shining  plates,  greasy  to  the  touch,  lighter 
than  water,  and  much  resembling  cholestei-in  in 
appearance  ;  it  is  distinguished  from  that  substance 
by  its  insolubility  in  ether.  It  is  slightly  soluble 
in  cold  water,  and  very  soluble  in  boiling  water, 
soluble  in  600  parts  of  cold  absolute  alcohol,  very 
insoluble  in  ether,  melting  point  170°  C.  ;  is  decom- 
posed by  nitrous  acid,  leucic  acid  being  formed  and 
nitrogen  given  off.  Distilled  with  dilute  sulphuric 
acid  and  manganese  peroxide,  it  yields  valei'O-nitrile, 


170 


Clinical  Chemistry. 


[Chap.  IV. 


carbonic  acid,  and  water.  Fused  with  caustic  potash 
it  is  transformed  into  potassium  valerate,  hydrogen, 
and  ammonia. 

127.  Tyr©siM  CgH^NOg  is  invariably  associated 
with  leucin.  To  obtain  it  from  the  urine  ;  precipitate 
the  colouring  and  extractive  matters  with  basic 
lead  acetate,  and  filter;  decompose  the  filtrate  with 
sulphydric  acid  and  filter ;  the  clear  filtrate  is  to  be 
concentrated,  and,  on  cooling,  crystals  of  ty rosin  will 
be  deposited.  The  crystals  form  long  prismatic  needles, 
which  chister  together  to  form  stellate  groups  \  some- 
times, when  obtained  from  urine,  these  groups  are  so 
closely  aggregated  together  as  to  form  balls  of  spicu- 
lated  needles  (Fig.  15,  6),  The  crystals  are  sparingly 
soluble  in  cold  water  and  alcohol ;  soluble  in  boiling 
water  and  in  acid  and  alkaline  solutions,  the  solubility 
being  increased  by  the  presence  of  extractive  matters  ; 
insoluble  in  ether. 

Tyrosin  treated  with  nitric  acid  turns  an  orange- 
red  colour,  which  becomes  yellow  on  heating ;  this 
touched  with  a  drop  of  liquor  sodse  acquires  a  red  tinge. 

128.  Mmcus  and  pus. — Pure  mucus  forms  a 
clear  translucent  mass;  mingled  with  it,  however,  are 

epithelial  cells  derived  from 
various  parts  of  the  genito- 
urinary tract  (Fig.  16)  and 
pigmentary  particles.  Per- 
fectly healthy  urine  always 
contains  a  small  quantity 
of  mucus,  which,  if  the 
urine  be  allowed  to  stand 
in  a  glass  vessel,  will  be 
seen  diffused  as  a  fine  cloud 
in  the  lower  stratum.  The 
epithelium  is  composed  of 
bladder    epithelium     (Fig. 


Fig.  16. — Epithelium  in  Urine. 


1  6,  d),  mixed,  in  the  case  of  women,  with  the  epithelium 


Chap.  IV.]  Pus   AND    MuCUS.  1  7  I 

from  the  vagina.  "When  mucus  is  increased  in  quantity 
by  any  morbid  condition  of  the  genitourinary  tract, 
we  have  in  addition  mucus  corpuscles,  and  epithelium 
from  the  part  of  the  tract  aflected  ;  as  small  rounded 
renal  cells  (Fig.  IG,  a)  and  casts  in  nephritis;  larger 
rounded  cells  (Fig.  IG,  6)  from  the  pelvis  and  kidm^y; 
columnar  cells  (Fig.  16,  f)  from  the  ureter,  or  urethra  ; 
or  large  cancer  cells  in  cancer  of  bladder,  and  granular 
masses  in  tubercular  disease.  Pus  is  generally  present  in 
the  urine  containing  an  excess  of  mucus ;  its  presence 
is  indicated  by  traces  of  albumin  derived  from  the 
liquor  puvis.  To  distinguish  diO'ei'entially  between  pus 
and  mucus,  when  both  are  present,  is  oftentimes  some- 
what diflicult,  especially  if,  in  addition  to  the  albumin 
deri\ed  from  the  liquor  pui'is,  there  is  albuminuria 
from  kidney  disease.  The  following  reactions  will  aid 
us  in  coming  to  a  conclusion  :  {a)  the  addition  of 
liquor  potassaj  to  a  urine  containing  an  excess  of 
pus  renders  it  thick  and  gelatinou.s,  whereas,  if  mucus 
be  in  excess  it  is  rendei-ed  thinner ;  {h)  mercuric 
chloride  added  to  the  urine,  if  pus  is  present,  the 
pyin  is  precipitated,  but  not  mucin  ;  the  precipitate 
should  be  filtered  oil',  and  if  mucin  is  present  it  will 
be  precipitated  from  the  filtrate  on  the  addition  of 
acetic  acid ;  (c)  under  the  microscope  it  is  difficult  to 
distinguish  mucin  corpuscles  from  pus  corpuscles  and 
other  young  cell-forms,  all  swelling  up  and  losing  their 
granular  surface,  whilst  the  niiclei  become  more  visible 
on  the  addition  of  acetic  acid ;  if,  however,  mucus  is 
in  excess,  a  coagulation  will  often  occur  in  the  fluid 
when  a  drop  of  acetic  acid  is  added,  from  precipitation 
of  the  mucin.  The  clinical  character  of  the  urine  also 
may  afibrd  a  clue.  When  mucus  is  in  excess,  the  urine 
s})eedily  undci'goes  acid  fermentation  and  becomes 
more  acid,  which  speedily  passes  on  to  ammoniacal 
fermentation.  Purulent  urine  is  usually  neutral, 
and  undergoes  alkaline  fermentation  slowly.     Urines 


T]2  Clinical  Chemistry.  [Chap.  iv. 

containing  an  excess  of  mucus,  if  acid,  friequently  de- 
posit the  mucin  in  small  shreds  and  cylinders,  these 
are  soluble  in  liquor  potassse.  On  the  other  hand, 
purulent  urine,  when  alkaline,  deposits  white  ropy 
strings,  which  are  soluble  in  acid. 

Extraneous  substances. — Fungi,  entozoa,  hair  from 
dermoid  cysts,  foetal  bones,  etc.,  may  all  find  their 
way  into  the  urine,  and  are  best  recognised  by  their 
microscopic  appearance.  Sand,  cane-sugar,  mortar, 
etc.,  may  be  added  by  hysterical  patients  for  the  pur- 
pose of  deceiDtion. 

129.  Detection  of  lead  in  nrine. —  Many 
organic  and  inorganic  poisons  a-re  eliminated  by  the 
kidneys  aad  pass  into  the  urine.  In  cases  of  poison- 
ing by  these  substances,  however,  it  is  more  usual  to 
examine  the  vomit  and  faeces  than  the  urine,  or  if  the 
patient  has  died,  to  seek  for  them  in  the  tissues.  The 
method  to  be  employed  in  these  cases  is  described 
§  151.  It  is  convenient  here  to  describe,  however, 
the  process  for  the  detection  of  lead  in  urine,  as  it 
is  frequently  required  for  clinical  purposes  in  cases  of 
plumbism,  to  watch  the  gradual  elimination  of  lead 
under  treatment,  especially  after  the  administration  of 
potassium  iodide.  As  the  amount  of  lead  is  often 
extremely  minute,  the  whole  twenty-four  hours'  urine 
should  be  employed.  This  should  be  evaporated  to  a 
treacly  residue  in  a  large  porcelain  dish,  and  this 
transferred  to  a  platinum  or  porcelain  crucible,  and 
heat  applied,  gently  at  first,  till  nothing  but  a  grey  ash 
is  left.  The  soluble  salts  are  then  removed  by  the 
addition  of  boiling  distilled  water,  till  a  drop  of  the 
washings  gives  no  residue  when  evaporated  on  a 
glass  slide.  The  washings  are  to  be  examined  with 
sulphydric  acid,  to  see  that  they  contain  no  lead. 
The  residue  is  then  treated  with  equal  parts  of 
distilled  water  and  niti'ic  acid,  and  the  mixture  boiled 
for  a  few  minutes ;  it  is  then   filtered,  and  the  filtrate 


Chap,  v.]  Saliva.  173 

tested  for  lead:  (1)  By  the  addition  of  sulphydric 
acid,  giving  a  black  sulphide  of  lead ;  (2)  potas- 
sium iodide,  a  yellow  precipitate  of  lead  iodide  ;  (3) 
potassium  chromate,  a  yellow  precipitate  of  lead 
chromate,  insoluble  in  dilute  acids.  These  precipitates, 
together  with  the  residue  not  dissolved  by  the  nitric 
acid,  and  the  precipitate  given  by  the  sulphydric  acid, 
if  any,  with  the  first  washings  with  hot  distilled  water, 
must  be  placed  on  a  filter  and  dried.  The  dried  resi- 
due mixed  with  sodium  carbonate,  and  the  mixture 
])laced  on  charcoal  and  fused  by  the  blow-pipe,  when 
a  bead  of  metallic  lead  will  be  obtained,  which  repre- 
sents the  whole  of  the  lead  present  in  a  metallic  state 
in  the  twenty-four  hours'  urine. 

130.  Urinary  calculi.  —  {^See  Morbid  products, 
chapter  vi.) 


CHAPTER   Y. 

MORBID    CONDITIONS    OF    THE    DIGESTIVE    SECRETIONS. 

131.  Saliva,  as  presented  for  clinical  exami- 
nation, is  mixed  with  oral  mucus,  and  oftentimes  con- 
tains portions  of  food  in  a  state  more  or  less  decom- 
posed. It  may  be  obtained  fairly  pure  by  directing 
the  patient  to  wash  his  mouth  out  thoroughly 
with  a  dilute  warm  solution  of  bicarbonate  of  soda, 
and  afterwards  ynih.  cold  spring-water.  The  inside  of 
the  mouth  should  then  be  lightly  brushed  with  a 
glass  rod  moistened  with  a  little  dilute  acid,  when  the 
mouth  will  fill  with  a  considerable  amount  of  clear 
viscid  fluid.  To  obtain  saliva  absolutely  pure, 
however,  a  small  canula  should  be  introduced  into 
the  ducts  of  the  respective  glands.  The  saliva 
obtained  from   the  parotid   and  submaxillary  glands 


174  Clinical  Chemistry.  [Chap.  v. 

diflfers  in  quality ;  the  former  being  ricli  in  ptyalin 
and  poor  in  mucin,  whilst  the  submaxillary  gland 
contains  a  considerable  amount  of  mucin,  and  but 
little  ptyalin.  The  physiological  effect  of  the 
stimulation  of  the  nerves  supplying  these  two  glands 
has  been  thoroughly  investigated  and  recorded  in 
physiological  text  -  books.  Here  it  will  only  be 
necessary  to  recall  the  results.  Thus,  stimulation  of 
the  parotid  by  Jacobson's  nerve,  leads  to  a  watery  secre- 
tion, containing  little  albumin,  ptyalin,  and  salts.  Irri- 
tation of  the  sympathetic  causes  no  secretion,  but  irri- 
tation of  both  Jacobson's  nerve  and  the  sympathetic  at 
the  same  time,  gives  rise  to  an  abundant  secretion,  in 
which  the  organic  constituents  abound,  but  the  salts 
are  only  slightly  increased.  With  the  submaxillary 
gland,  stimulation  of  the  chorda  tympani  produces  an 
increased  flow  of  saliva  ;  if,  however,  the  stimulation 
be  directed  to  the  sympathetic  filament  exclusively, 
the  secretion,  though  abundant,  becomes  thicker  and 
more  gelatinous  than  from  stimulation  of  both  filaments. 
Section  of  the  nerves  without  stimulation  often  leads 
to  the  discharge,  for  days  and  weeks  together,  of  a  thin 
aqueous  saliva,  the  so-called  paralytic  saliva.  Atropin, 
as  is  well  known,  paralyses  the  action  of  the  gland, 
but  other  substances,  such  as  pilocai'pin  and  eserin, 
stimulate  the  secretion.  Langley  has  shown  {Journal 
of  Physiology,  vol.  i.),  that  by  injecting  atropin  into 
the  duct  of  the  submaxillary,  the  secretion  can  be 
stopped,  but  by  injection  of  pilocarpin  it  is  re- 
stored. The  sublingual  and  buccal  glands  also 
secrete  saliva ;  but  in  the  human  subject  their 
secretion  cannot  be  obtained  separately  for  examina- 
tion, since  it  involves  tying  the  ducts  of  the  other 
glands. 

The  mixed  saliva  has  the  following  approximate 
composition  in  1,000  parts  :  Water  994-94  ;  Solids  5'06 
(ptyalin  1*2,  mucin  1"3,  fatty  matters  1"1,  salts  1"6). 


Chap.  V.)  Saliva.  175 

The  ptAjalin,  or  diastatic  ferment,  may  be  separated 
approximately  pure  by  precipitating  fresh  saliva  with 
dilute  normal  phosphoric  acid,  and  then  adding  lime- 
water  ;  filter  otl'  precipitate,  and  dissolve  it  in  distilled 
water,  from  which  it  is  to  be  precipitated  by  alcohol, 
collected  on  a  lilter,  washed  repeatedly  with  a  mixture 
of  alcohol  and  water,  dried,  and  weiglicd.  As  ptyalin, 
however,  has  never  been  obtained  quite  pure,  its 
chemical  composition  and  reactions  are  doubtful, 
except  its  energetic  action  on  starch,  which  it  converts 
into  maltose  and  glucose.  Mucin  may  be  obtained  by 
allowing  saliva  to  fall  into  a  beaker  containing  some 
dilute  acetic  acid,  when  it  will  deposit  in  stringy 
flakes ;  these  should  be  collected  on  a  filter,  and 
washed  with  alcohol,  dried,  and  weighed.  Pure 
saliva  also  contains  traces  of  serum  albumin  and 
serum  globulin.  The  fatty  matters  are  estimated 
from  the  etherial  residue  as  for  blood  (§  93).  The 
inorganic  residue  is  estimated  (a)  from  the  bases 
by  incinei'ation  (§101);  (h)  from  the  acids  by  volumetric 
determination  directly  from  the  saliva,  after  the 
removal  of  the  organic  constituents,  as  with  the 
estimation  of  phosphoric,  hydrochloric,  and  sulphuric 
acid  in  urine  (§§  113,  114,  115).  The  salts  consist 
chiefly  of  calcium  phosphate,  and  carbonate,  and  are 
deposited, unless  care  is  taken, roinid  the  teeth  as  tartar; 
.sometimes  they  deposit  in  the  salivary  ducts,  and  form 
a  calculus.  The  saliva  also  contains  potassium  sulpho- 
cyanate,  which  is  of  some  interest,  from  a  medico-legal 
point  of  view,  in  opium  poisoning  (§§  83,  136). 

The  variation  in  the  quality  and  quantity  of  saliva 
excreted  under  various  morbid  conditions  has  been  very 
inadequately  studied.  The  following  are  the  chief  facts 
of  importance  that  have  been  ascertained.  The  average 
daily  amount  excreted  has  been  placed  at  1,500  grms.  ; 
this  is  probably  too  high,  and  800  to  900  grms.  is  nearer 
the  mark.     The  daily  excretion  is  increased  by  dry 


176  Clinical  Chemistry.  [Chap.  v. 

food.  The  excretion  is  diminished  in  pyrexia,  and  by  \ 
the  action  of  certain  drugs,  particularly  belladonna.  • 
Claude  Bernard  found  that  dilute  alcohol,  dilute 
alkaline  solutions,  and  saliva  were  all  powerful 
excitants  of  the  gastric  secretion  when  introduced 
into  the  stomach  by  means  of  a  gastric  fistula;  but  of 
the  three  saliva  was  the  most  powerful.  Saliva,  then, 
must  be  regarded  as  having  a  twofold  function  ;  its 
diastatic  action,  and  as  an  exciter  of  gastric  secretion. 
Diminution  of  its  secretion  must  therefore  lessen  the 
digestive  powers,  both  as  regards  the  albuminoiis  as 
well  as  the  starchy  constituents  of  the  food.  The 
saliva  of  new-born  infants  has  no  diastatic  action  on 
starch.  The  normal  reaction  of  saliva  is  alkaline,  it 
is  often  neutral,  sometimes  acid.  The  acidity  in  most 
cases  is  due  to  decomposition  of  organic  substances  in 
the  moutli,  though  in  some  diseases,  as  diabetes,  acute 
rheumatism,  and  mercurial  salivation,  the  saliva  is 
acid  as  it  comes  from  the  ducts  of  the  glands.  The  dias- 
tatic action  of  saliva  is  best  manifested  in  dilute  alkaline 
solutions  at  40°  C,  but  it  also  acts  in  neutral  and  very 
dilute  acid  solutions ;  strong  alkalies  and  acids,  and 
temperatures  above  70°  C,  stop  its  action  entirely. 
In  conditions  of  debility,  and  under  the  influence  of 
certain  drugs  (sialogues),  of  which  mercury,  pilo- 
carpin,  and  eserin  are  the  chief,  the  amount  dis 
charged  in  the  twenty-four  hours  is  greatly  increased. 
In  water  brash  the  aqueous  discharge  from  the  mouth 
undoubtedly  proceeds  in  great  measure  from  the  salivary 
glands.  Salivation  is  often  met  with  in  hysterical 
females,  and  is  sometimes  of  an  intermittent  character. 
I  have  noticed  profuse  salivation  after  injury  to  the 
upper  part  of  the  food  tube  in  a  case  of  attempted 
sulphuric  acid  poisoning ;  the  sialorrhsea  came  on  some 
time  after  the  separation  of  the  eschars  and  healing  of 
the  ulcers.  Physiological  remedies  were  tried  without 
avail,  and  the  salivation  contintied  till  the  patient's 


Chap,  v.]  S.l LIVA  TION.  I  7 '/ 

general  health  was  restored,  when  it  gradually  subsided. 
Altered  saliva  is  often  retched  up  from  the  stomach 
in  cases  of  chronic  gastric  catarrh,  especially  that  form 
dependent  on  alcoholism.  This  retching  is  most 
frequent  in  the  morning,  and  stringy  masses  are 
bi'ought  up.  These  consist  of  mucin  derived  from 
the  saliva  swallowed  during  sleep,  and  deposited  from 
it  by  th6  action  of  the  acetic  and  other  acids,  produced 
by  fermentative  action  going  on  in  the  stomach,  just 
in  the  same  way  as  mucin  is  thrown  down  from  saliva 
when  dropped  into  a  vessel  containing  dilute  acetic 
acid. 

Salivation,  as  is  well  known,  follows  the  continued 
use  of  mercury  ;  and  extremely  minute  doses  will,  \vith 
some  people,  rapidly  induce  the  condition.  In  most 
instances  we  can  trace  the  salivation  to  the  use  of  the 
drug ;  but  in  some  cases,  when  it  has  been  accidentally 
introduced  into  the  system,  either  by  the  stomach 
in  quack  medicines,  or  through  the  skin  by  handling 
some  material  the  deleterious  nature  of  which  was 
unknown,  it  becomes  necessary  to  examine  the  saliva 
in  order  to  discover  the  presence  of  mercury,  and  so 
get  a  clue  to  the  cause  of  the  salivation. 

132.  Detection  of  mercury  in  saliva. — For 
this  purpose  the  saliva  is  to  be  collected  for  twenty-four 
hours,  and  dilute  hydrochloric  acid  (one  part  of  acid 
to  nine  parts  of  water)  added  to  it.  The  mixture  is 
heated  for  two  hours  in  a  water-bath,  filtered,  and  the 
filtrate,  which  should  be  labelled  a,  concentrated  to 
half  its  bulk.  The  precipitated  matters  in  the  filter 
are  then  placed  in  a  beaker,  filled  three  parts  full 
with  dilute  hydrochloric  acid  (one  part  acid  to  six 
water),  and  the  whole  heated  over  a  water-bath, 
adding  from  time  to  time  small  quantities  of  potassium 
chlorate,  and  constantly  stirring  to  dissolve  the 
organic  residue.  When  this  is  completely  dissolved, 
filter,   and   add   filtrate   to   the    previous   filtrate    a. 

M 


178  Clinical  Chemistry.  [chap.  v. 

Concentrate  the  mixed  filtrates  to  one-fourtli  their 
bulk.  The  solution  contains  any  mercury  that  may 
be  present  as  bichloride.  To  prove  the  presence  of 
mercury,  (1)  place  a  drop  of  the  solution  on  a  gold  or 
copper  coin,  and  touch  with  blade  of  knife ;  a  bright 
silvery  stain  vi^ill  appear.  (2)  Place  a  few  strips  of 
fiire  copper-foil  in  a  test-bube,  and  add  a  little  of  the 
solution,  and  boil ;  the  mercury  will  be  deposited  on 
the  surface  of  the  copper-foil.  Remove  the  strips  and 
wash  them  with  very  dilute  solution  of  ammonia,  and 
dry  them  between  blotting-paper.  Then  place  them  at 
the  bottom  of  a  narrow  glass  tube  (German  glass), 
and  apply  heat ;  the  mercury  will  be  volatilised,  and 
deposited  as  a  ring  of  minute  globules  at  the  upper 
end  of  the  tube.  The  character  of  these  globules 
can  generally  be  recognised  by  the  eye.  If,  however, 
they  are  too  small,  remove  the  strips  of  copper  from  the 
tube,  and  dissolve  the  ring  by  the  addition  of  a  drop 
or  so  of  dilute  nitro-muriatic  acid,  and  gently  evapo- 
rate the  solution.  Dissolve  the  residue  in  a  little 
water,  and  divide  into  two  equal  portions  ;  (a)  tested 
with  a  drop  of  dilute  solution  of  potassium  iodide, 
it  gives  a  red  precipitate  of  mercuric  iodide,  soluble 
in  excess  of  potassium  iodide  solution ;  (6)  a  drop 
added  to  solution  of  caustic  potash  gives  a  yellow 
precipitate  of  hydrated  mercuric  oxide,  insoluble 
in  excess  of  liquor  potassse.  (This  process  is 
available  for  the  detection  of  mercury  in  the  solid 
tissues,  care  being  taken  to  divide  them  very  finely 
before  treating  with  hydrochloric  acid  and  potassium 
chlorate.) 

133.  Gastric  juice  is  generally  obtained  for 
examination  from  a  gastric  fistula  in  animals,  and  con- 
tains saliva,  unless  the  precaution  of  previously 
tying  the  ducts  of  the  salivary  glands  has  been 
adopted.  The  following  is  an  approximate  analysis 
of  gastric  juice  obtained  from  the  human  subject,  and 


Chap.  V.)        Acidity  OF  Gastiuc  Juice.  179 

which,  of  course,  contains  a  certain  amount  of  saliva  : 
Water,  994-6;  Solids,  5-4;  i)ei)sin  3-02,  free  hydro- 
chloric acid  0'22,  alkaline  chlorides  2'0,  phosphates 
of  lime,  magnesia,  and  iron,  0"15. 

134.  Reaction  of  flic  gastric  juice  is  acid, 
and  varies  considerably,  according  to  the  statements  of 
difierent  observers.  Thus,  Richet,  from  numerous 
observations  on  a  patient  after  gastrotomy,  gives  the 
average  acidity  as  1"7,  with  a  maximum  of  3'4  and  a 
minimum  of  0'5  per  thousand  ;  Schroder,  from  obser- 
vations made  in  a  female  with  gastric  fistula,  records 
it  as  low  as  0*2  ;  Schmidt,  from  experiments  on  dogs, 
gives  an  average  of  2  "5,  and  Szabo,  with  the  same 
animals,  3*  per  thousand.  These  variations  need  not 
be  considered  contradictory,  the  acidity  of  the  gastric 
juice  no  doubt  depending  much  on  the  nature  of  the 
physiological  stimulus  that  excites  it.  This  supposi- 
tion receives  support  from  the  observations  of  Schmidt, 
who  found  the  juice  of  herbivorous  animals  had  a 
lower  degree  of  acidity  than  that  from  carnivorous 
animals.  One  point,  however,  is  certain,  that  the 
acid  is  present  in  a  very  dilute  state,  thus  confirming 
the  results  obtained  by  experiments  with  artificial 
gastric  juice,  in  which  a  degree  of  acidity  of  0'2  per 
cent,  of  hydrochloric  acid  is  found  to  be  most  effective. 
With  I'egard  to  the  amount  of  acid  withdrawn  from 
the  blood  by  the  gastric  secretion  during  the  twenty- 
four  hours,  it  is  impossiljle  to  speak  with  any  certainty, 
since  the  quantity  of  gastric  juice  secreted  during  that 
period  has  never  been  definitely  ascertained.  Griine- 
wald,  in  a  case  examined  by  him,  states  it  as  t^Venty- 
three  imperial  pints,  but  this  was  undoubtedly  Under 
Jiatliological  conditions.  Parkes  considers  if  we  put 
it  at  twelve  pints  we  shall  be  within  the  mark. 
Lehmann,  drawing  conclusions  from  experiments  on 
animals,  concludes  that  the  secretion  of  gastric  juice 
in  the  twenty-four  hours  amounts  to  one-tenth  of  the 


i8o  Clinical  Chemistry.  [Chap.  v. 

whole  weight  of  their  body.  This,  per  man,  would 
represent  something  like  14  lbs.  avoirdupois.  Un- 
fortunately^  as  E,ichet  well  observes,  the  data  upon 
which  these  calculations  are  founded  are  very  uncer- 
tain, since  it  is  extremely  difficult  to  determine  the 
relative  proportion  of  the  true  gastric  secretion 
from  the  mucus  mixed  with  it,  and  also  to  make 
allowance  for  what  passes  off  accidentally  during 
the  experiment  by  the  pylorus,  and  what  is  absorbed 
by  the  veins  of  the  stomach.  Moreover,  even  if 
these  obstacles  should  be  overcome,  the  intermittent 
nature  of  the  secretion  would  make  it  difficult 
to  arrive  at  very  definite  conclusions.  It  has  now 
been  incontestably  proved  that  the  acidity  of  the 
gastric  juice  is  due  to  free  hydrochloric  acid.  Eichet 
has  shown  that  in  the  fresh  secretion  this  is  the  only 
mineral  acid  present.  Lactic,  acetic,  and  butyric 
acids  are  also  met  with  in  gastric  juice,  the  result  of 
fermentative  changes  occurring  in  the  stomach.  In 
certain  morbid  conditions  they  may  be  considerably 
in  excess  of  the  hydrochloric  acid  (indeed,  that  acid 
may  be  very  scantily  secreted),  and  thus,  by  causing 
delay  in  gastric  digestion,  lead  to  the  formation  of 
these  organic  acids.  In  many  cases  of  acid  dyspepsia 
it  is  a  matter  of  importance  to  determine  whether 
the  acid  in  the  vomited  matters  contains  a  due  pro- 
portion of  hydrochloric  acid,  or  whether  the  organic 
acids  are  in  excess.  In  the  former  case,  the  acidity 
will  arise  from  hyper-secretion  ;  in  the  latter,  from 
fermentative  changes  ;  or  both  acids  may  be  in  excess. 
Till  recently  we  had  no  ready  means  of  determiniiig 
the  nature  of  the  acid  present  in  the  vomited  matters, 
and  therefore  uncertainty  frequently  existed  as  to  the 
conditions  under  which  the  acids  expelled  were  formed 
in  the  stomach.  Richet,  however,  has  suggested  a 
method  by  which  the  nature  of  the  acid  can  be 
accurately  determined,  and  has  thus  supplied  us  with 


Chap,  v.]  CO-EF-FICIENT   OF   PaRTAC.E.  i8i 

an  additional  means  of  diagnosis  in  those  cases  of 
•stomach  diseaso  attended  with  the  vomiting  of  acid 
matters.  His  mc^thod  is  based  on  the  fact  tliat  if  an 
aiiueous  acid  sohition  be  sliaken  with  ether  the  latter 
removes  a  constant  quantity  of  the  acid.  This,  in 
the  case  of  mineral  acids,  is  extremely  small,  but  with 
organic  acids  the  removal  is  considerable.  The  specific 
ratio  which  exists,  after  an  aqueous  solution  of  acid 
has  been  agitated  with  ether,  between  the  quantity  of 
acid  taken  up  by  a  certain  volume  of  ether  and  that 
which  remains  in  an  equal  volume  of  the  solution 
after  it  has  been  treated  with  ether,  is  called  the  "  co- 
efficient of  partage,"  a  term  originally  applied  by 
Berthelot.  The  co-efficient  of  pai'tage,  in  the  case  of 
mineral  acid,  is  high  (above  500)  because  the 
quantity  of  acid  yielded  to  the  ether  is  small ;  the  co- 
efficient for  the  organic  acids  is  low,  for  the  opposite 
reason.  The  following  example  will  render  the  matter 
clearer  :  lUO  grammes  of  water  containing  11  grammes 
of  lactic  acid,  and  100  grammes  of  ether  agitated 
with  this  solution  removes  1  gramme  of  acid  ;  so 
when  we  determine  the  acidity  of  the  two  fluids  we 
lind  that  of  the  water  to  be  10  and  that  of  the  ether 
1.  But  supposing  the  degree  of  dilution  to  be  ten 
times  gi'eater  than  in  the  tirst  case,  then  100  grammes 
of  water  whicli  contain  1"1  grammes  of  lactic  acid, 
agitated  with  an  equal  weight  of  ether,  will  yield  to 
the  ether  O'l  gramme,  and  retain  1  gramme,  the  co- 
efficient of  lactic  acid  is  therefore  said  to  be  10.  The 
co-efficients  of  many  other  organic  acids  have  been 
determined.  Some  of  the  most  important,  as  having  a 
bearing  on  animal  chemistry,  are  succinic  acid  c'=6, 
benzoic  acid  c'=l'8,  oxalic  acid  c'=9'5,  acetic  acid 
c'=l'4.  So  far  as  concerns  one  acid  in  solution  the 
operation  is  simple  enough ;  but  when  we  have  to  deal 
with  a  mixture  of  two  or  more  we  must  have  recourse 
to  a  series  of  agitations  with  ethei",  so  that  we  may 


1 82  Clinical  Chemistry.  [chap.  v. 

separate  tlie  acid  which  is  the  most  readily  soluble  in 
ether  from  the  one  that  is  less  so.  By  such  repeated 
treatment  of  the  original  acid  solution  with  ether,  and 
recording  the  co-efficient  of  partage  after  each  opera- 
tion, we  are  able  to  obtain  the  true  co-efficient  of 
partage  for  each  acid.  E,ichet  has  found  by  repeated 
experiments  that  gastric  juice,  when  freshly  taken 
from  a  fistula,  has  a  high  co-efficient  of  partage  corre- 
sponding to  that  of  hydrochloric  acid,  whilst  by 
keeping  the  juice  some  time  the  co-efficient  of  partage 
gradually  fell,  denoting  the  increase  of  the  organic 
acids  from  fermentative  changes  taking  place  in  the 
secretion.  Another  argument  pointing  conclusively 
in  favour  of  the  acidity  of  the  gastric  juice  being  due  to 
hydrochloric  acid,  is  that  if  we  estimate  the  bases  and  the 
chlorine  separately,  we  find  that  there  is  more  chlorine 
than  is  required  to  convert  all  the  bases  into  chlorides. 
As  Ewald  remarks,  the  excess  of  chlorine  can  only 
exist  as  free  hydrochloric  acid,  or  in  an  organic 
combination.  In  addition  to  this,  the  fact  that  the 
determined  acidity  of  the  gastric  juice  as  obtained 
experimentally  by  means  of  fistulse  closely  corresponds 
with  the  degree  of  acidity  at  which  the  artificial 
gastric  juice  is  most  active  (viz.,  0*2  per  cent,  of 
hydrochloric  acid),  is  another  point  proving  that 
hydrochloric  acid  is  the  acid  concerned  in  gastric 
digestion,  since  it  has  been  shown  experimentally  that 
when  artificial  gastric  juice  is  prepared  with  lactic 
acid  instead  of  hydrochloric  acid,  a  degree  of  acidity 
six  times  greater  than  the  natural  acidity  of  the 
gastric  juice  is  required  to  effect  digestion,  whilst  if 
acetic  acid  is  employed  the  degree  of  acidity  required 
is  twice  as  great. 

We  must  now  proceed  to  consider  the  manner  in 
which  the  hydrochloric  acid  of  the  gastric  juice  is 
separated  in  a  free  state  from  the  alkaline  blood.  It 
is  only  recently  that  an  explanation  has  been  offered 


Chap,  v.]         Acidity  OF  Gastric  Juice.  183 

to  account  for  this  seeming  paradox.  In  1874,*  in 
order  to  elucidate  this  point,  I  made  in  the  lahoratory 
of  the  Charing  (^i-oss  hospital  a  series  of  experiments, 
iu  wliich  1  found,  liy  introducing  an  alkaline  solution 
consisting  of  sodium  bicarbonate  (5  per  cent.)  and 
neutral  sodium  phosphate  (5  per  cent.)  into  a  small 
U-tube,  fitted  witli  a  diaphragm  at  the  bend,  and 
passed  a  weak  electric  current  through  the  solution, 
that  in  a  short  time  the  lluid  in  the  limb  connected 
with  the  negative  pole  increased  in  alkalinity,  whilst 
the  fluid  in  the  limb  connected  with  the  positive  pole 
became  acid  from  the  formation  of  acid  sodium 
phosphate.  Now,  one  of  the  chief  salts  in  the  blood 
is  undoubtedly  sodium  or  potassium  bicarbonate,  an 
acid  salt  with  an  alkaline  reaction;  and  neutral  sodium 
jihosphate  has  also  an  alkaline  reaction.  The  decom- 
position Avhich  occurs  between  them  may  be  repre- 
sented as  follows  : 

Acid  sodium        Neutral  sodium      Normal  sodium  Acid  sodium 

carbouate.  pliospLate.  carbonate.  phosphate. 

NaH.COa   -t-  NaoHPO^  =  Na.HCO.,   -f   NaHoPO,. 

The  above  reaction  explains  the  presence  of  acid 
sodium  phosphate  in  urine.  To  account  for  the 
formation  of  free  hydrochloric  acid  in  the  gasti'ic  juice, 
sodium  chloride  is  substituted  for  the  neutral  sodium 
phosphate,  the  decomposition  in  this  case  being 


Acid  sodium 
ciirbouate. 

Sodium 
chloride. 

Normal  sodium 
carbonate. 

Hydrochloric 
acid. 

NaHoCOo      - 

t-      NaCl      = 

=      Na.,HCOo 

-1-    HCl. 

Maly,  however,  who  subsecpiently  investigated 
(1877)  the  subject  with  great  care,  has  come  to  the 
conclusion  that  the  hydrochloric  acid  is  derived  from 

*  Lancet,  p.  29,  July  4th,  1874. 


184  Clinical  Chemistry.  [Chap. v. 

the  decomposition  of  neutral  sodium  phosphate  with 
calcium  chloride,  as  described  §§  79 — 84. 

Practi<"ally,  it  matters  little  which  view  we  adopt, 
since  all  the  salts  named  are  present  in  the  blood  ;  the 
important  fact  being,  that  out  of  the  body  a  weak 
electrical  current  will  separate  the  acid  from  its  base. 
Whether  the  decomposition  occurring  in  the  body  is 
due  to  the  same  agency  must  for  the  present  remain  a 
matter  of  conjecture.  Whatever  be  the  nature  of  the 
agency  that  causes  the  decomposition,  it  must  be  a 
powerful  one  to  effect  the  separation  of  hydrochloric 
acid  from  bases  for  which  it  has  such  a  strong  affinity 
as  soda  or  lime.  The  decomposition,  however,  once 
effected  in  the  blood,  there  is  no  difficulty  in  explain- 
ing the  presence  of  free  hydrochloric  acid  in  the 
stomach,  since  Graham  showed  many  years  ago 
that  this  acid  possesses  high  diffusive  power,  and 
passes  from  a  mixture  through  a  dialyser  with  great 
rapidity. 

135.  Pepsin  is  most  conveniently  prepared  by 
dissecting  off  the  mucous  membrane  of  the  stomach 
of  a  recently  killed  animal,  rejecting  the  pyloric 
extremity.  The  mucous  membrane  is  then  sliced 
into  thin  shreds,  and  macerated  in  dilute  phosphoric 
acid  till  dissolved.  The  mixture  is  then  strained 
through  coarse  muslin,  and  the  filtrate  precipitated 
with  an  equal  volume  of  lime-water.  The  precipitate 
is  collected  in  a  filter,  well  washed,  and  dissolved  in 
dilute  hydrochloric  acid.  The  solution  is  then  placed 
in  a  glass  flask,  and  a  saturated  solution  of  cholesterin, 
in  one  part  of  ether  and  four  parts  of  alcohol,  is 
passed  down  to  the  bottom  of  the  flask  by  means  of 
a  tube,  and  the  whole  mixture  well  agitated.  The 
cholesterin  separates,  mingling  with  the  pepsin.  The 
cholesterin  is  removed  by  repeated  treatment  with 
ether,  leaving  the  pepsin  as  a  greyish- white  powder, 
insoluble  in  water,  alcohol,  and  ether,  but  very  soluble 


Chap,  v.]  Pepsin.  185 

ill  dilute  acids.  The  acid  solutions  are  precipitated 
liy  alcohol,  and  by  ntmtral  and  basic  load  acetate,  but 
not  by  strong  nitric  acid,  tannic  acid,  or  mercuric 
t'hloride.  Pepsin  by  itsdf  has  no  action  on  albu- 
minous substances,  but,  in  conjunction  with  dilute 
acid,  converts  them  into  peptones.  By  this  conversion 
albuminous  substances  become  more  difTusible.  Tlius, 
taking  the  dillusion  rate  of  ordinary  albumin  at  100, 
we  find  that,  when  converted  into  peptone,  the 
diffusion  rate  is  7'1 — 9-9;  in  other  words,  it  is  in- 
creased about  twelve  times.  The  natural  acid  of  the 
gastric  juice  is,  as  stated  in  the  pi'eceding  para- 
graph, hydrochloric  acid,  and  the  degree  of  acidity  at 
which  digestion  is  best  effected  was  put  at  about 
0'2  per  cent,  of  the  real  acid.  The  proportion  be- 
tween the  quantity  of  acid  and  the  quantity  of 
pepsin  required  to  reduce  a  given  amount  of  albu- 
minous material  may  be  thus  stated.  If,  during 
artiticial  digestion,  the  process  comes  to  a  stop,  the 
addition  of  some  dilute  acid  Avill  set  it  going  again. 
After  a  time,  however,  the  addition  of  acid  is  not 
suflicient,  and  more  pepsin  has  to  be  added.  The 
quantity,  however,  of  pepsin  required,  as  compared 
with  the  quantity  of  albumin  digested,  is  really  very 
small.  The  action  of  gastric  juice  on  the  various 
food-stuffs  can  be  readily  studied  by  means  of  a 
glycerin  extract  of  pig's  stomach,*  and  a  0*2  per 
cent,  solution  of  HCl.  With  fats,  the  gastric  juice 
dissolves  the  albuminous  envelopes  of  the  fat  cells, 
whilst  the  temperature  (40°  C.)  at  which  digestion  is 
carried  on  renders  the  solid  fats  fluid,  but  no  real 
chemical  change  occurs.    Gastric  juice  has  no  action  on 

*  This  is  made  by  mincing  the  mucoiis  membrane  of  a  pig's 
stomach,  and  covering  it  with  glycerin.  After  standing  fortj'-cight 
hours,  the  glycerin  is  strained  off,  and  more  glycerin  added  to  the 
residue,  and  tliis  again  strained  off.  The  process  is  repeated  till 
all  the  pepsin  has  been  extracted. 


1 86        '  Clinical  Chemistry.  [Chap.  v. 

the  starchy  matters  of  the  food,  but  it  does  not  put  a 
stop  to  the  conversion  of  starch  into  glucose  by  the 
saliva.  Gastric  juice  dissolves  (^efc^im/erows  tissues; 
that  is,  gelatin,  after  digestion  with  artificial  gastric 
juice,  loses  the  power  of  gelatinising.  The  casein  of 
milk  is  coagulated  before  being  converted  into 
peptone ;  this  curdling  is  apparently  caused  by  some 
ferment  which  sets  up  lactic  acid  fermentation  (Ham- 
marsten)  of  the  milk  sugar,  and  is  not  due  to  the 
acid  of  the  gastric  juice  itself.  All  proteid  bodies, 
with  the  exception  of  lardacein,  are  converted  into 
peptones  by  the  action  of  pepsin  in  dilute  acid  solu- 
tions. The  circumstances  chiefly  influencing  gastric 
digestion  may  be  thus  enumerated  :  Digestion  pro- 
ceeds best  at  temperatures  between  35°  and  40°  C.  ; 
boiling  destroys  all  action ;  neutralisation,  or  the 
presence  of  too  much  acid,  arrests  the  action ;  the 
concentration  of  the  products  of  digestion  retard 
digestion ;  minute  subdivision,  by  increasing  the 
surface  acted  on  by  the  gastric  juice,  favours 
digestion ;  alcohol,  strong  alkaline  mixtures,  and 
salts  of  the  heavy  metals,  also  interfere  with  the 
process. 

135  a.  Peptones,  as  obtained  by  the  action  of 
gastric  juice  on  proteid  substances,  are  white  amor- 
phous bodies,  giving  an  acid  reaction  to  litmus  paper, 
soluble  in  water.  Their  solutions  are  not  coagulable 
by  heat,  nor  by  mercuric  salts,  tannic  acid,  mineral 
a^ids,  or  alkalies.  Bile,  added  to  an  acid  solution  of 
peptone,  precipitates  it.  The  reason  of  this  is  not 
clear ;  it  is  probably  analogous  to  the  precipitation  of 
parapeptone  that  occurs  on  neutralisation  with  sodium 
carbonate.  When  quite  pure,  i.e.,  free  from  un- 
digested albumin,  they  should  give  no  reaction  with 
Millon's  test  or  the  xantho-proteic  reaction.  Mixed 
with  Fehling's  solution,  they  give  a  purple-violet ; 
but,  when  floated  on  the  surface,  the  coloration   at 


Chap.  V.)  Peptones.  187 

tlic  junction  of  the  two  fluids  is  rosy  red.  According 
to  Dr.  Guoi-ge  Jolinson,  thoy  are  precipitated  l>y 
picric  acid,  tlie  precipitate  being  re-dissolved  when 
heated.  This  last  reaction,  in  my  opinion,  is  due  to 
the  presence  of  a  bye-product,  parapeptone  or  hemi- 
albuniose,  rather  tlian  characteristic  of  the  true 
])eptone.  Tlie  peptones  all  possess  Isevo-rotatory 
power.  There  are  several  varieties  of  peptones. 
According  to  the  original  view  of  Meissner,  there 
is  a  bye -product  resembling  syntonin,  which  he 
called  parapeptone ;  intermediate  products,  called 
metapeptone  and  A  and  B  peptones ;  and  tlie  true,  or 
C,  peptone..  Kiihne  considers  that  the  initial  step  in 
botli  gastric  and  pancreatic  digestion  is  the  breaking 
up  of  albumin  into  anti-albui)iose  and  Jiemi-albumose. 
The  former  is  converted  into  anti-peptone,  which 
undergoes  no  further  change,  either  by  the  action  of 
gastric  or  pancreatic  digestion,  and  gives  the  reactions 
above  described  as  characteristic  of  true  peptone  ;  the 
latter  is  converted  into  hemi-peptone,  which,  by  the 
action  of  trypsin,  the  pancreatic  ferment,  is  converted 
into  leucin  and  tyrosin,  and  to  which  we  shall  refer 
when  speaking  of  the  pancreatic  juice.  With  regard  to 
the  two  bye-products,  anii-albumose  and  hemi-albumose, 
the  former  may  be  regarded  as  identical  with  Meiss- 
ner's  parapeptone,  and  the  latter  with,  his  a  peptone. 
With  regard  to  their  charactei'S,  anti-albumose,  or 
parapeptone,  is  insoluble  in  water,  soluble  in  dilute 
acids ;  and  the  acid  solution  is  precipitated  by  potas- 
sium ferrocyanide,  mercuric  chloride,  tannic  acid,  and 
picric  acid.  Hemi-albumose,  or  IMeissner's  A  peptone, 
is  soluble  in  water  at  70°  C,  but  is  re-precipitated  on 
cooling,  soluble  in  10  per  cent,  solutions  of  sodium 
chloride  ;  it  thus  resembles  the  "  albumin  "  found  in 
the  urine  of  a  case  of  osteo-malacia  by  Dr.  Bence 
Jones.  With  regard  to  the  composition  of  these 
bodies,  they  are   generally   regardetl    as   hydrates    of 


1 88  Clinical  Chemistry.  [Chap.  v. 

albuminate^  and  are  formed  by  albumin  taking  up 
water,  as  starcb  does  to  form  glucose.  Henninger  is 
said  to  have  proved  this  by  changing  peptone  back 
to  syntonin  by  the  abstraction  of  water.  The  clinical 
interest  attacliing  to  the  peptones  is  their  appearance 
in  urine  under  various  morbid  conditions.  The 
method  for  isolating  these  bodies  is  described  §  118, 
page  148. 

136.  Vomited  matters. — Vomiting  is  induced 
(«)  directly,  by  stimulation  of  the  stomach ;  (h)  indi- 
rectly, through  the  irritation  of  other  arid  distant 
organs.  In  the  first  category  we  have  to  consider  the 
vomiting  in  relation  to  disease  of  the  organ,  cancer, 
ulceration,  stricture  of  the  pylorus,  or  poisoning  by 
corrosive  poisons,  etc. ;  and  here  we  have  to  determine 
the  conditions  with  regard  to  the  digestion  of  the 
food  ingested,  the  acidity  of  the  gastric  secretion,  the 
presence  or  absence  of  blood  or  bile,  cancer  cells,  and 
sarcinse.  In  the  second  category,  viz.,  vomiting  pro- 
duced by  irritation  of  distant  parts,  the  retching 
produced  by  tickling  the  fauces  is  the  most  familiar ; 
but  reflex  vomiting  may  be  produced  by  irritation  of 
any  organ ;  thus,  the  vomiting  in  uterine  disease  on 
the  passage  of  renal  or  biliary  calculi ;  the  early 
vomiting  of  phthisis  and  in  disease  of  the  brain ;  or 
it  maybe  caused  through  the  nervous  system  by  toxic 
agents,  as  tobacco,  lobelia,  opium,  etc.  ;  or  by  blood 
poisons,  as  in  erysipelas,  septicsemia,  gout,  etc.  For 
clinical  purposes,  the  chemical  examination  of  vomited 
matters  may  be  limited  (1)  to  an  inquiry  into  the 
nature  of  acid  present,  whether  due  to  hyper- secretion 
of  gastric  juice  (excess  of  hydrochloric  acid),  or  from 
fermentative  changes  occurring  in  the  stomach  (excess 
of  lactic  or  acetic  acid) ;  (2)  the  detection  of  poisonous 
substances  in  the  vomit. 

(1)  Determining  amount  and  nature  of  acid 
present   in  vomit. — In  directing  our  treatment  with 


Chap,  v.]  Vo.i//r.  189 

regard  to  stomach  afTeotions  it  is  of  the  utmost  im- 
j)ortHnce  for  us  to  recognise  whether  the  acid  present 
in  the  vomited  matter  is  due  to  hyper-secretion  of 
gastric  juice  (hydrochloric  acid)  or  to  fermentative 
changes,  lactic  acid,  etc.*  Nor  is  it  sufficient  to 
rest  content  with  one  examination  only,  since  in 
these  cases  it  often  happens  that  both  forms  may  be 
present,  but  that  one  preponderates  more  at  one 
time  than  another.  Thus,  Dr.  Gokling  Bird  states 
that  in  a  case  of  scirrhous  pylorus  he  found  at 
one  time  a  quantity  of  free  hytlrochloric  acid  in  one 
pint  of  vomit  equal  to  twenty-two  grains  of  the 
pharmaceutical  acid,  with  an  organic  acid  sufficient  in 
quantity  to  neutralise  seven  grains  of  pure  potash. 
At  another  time  the  hydrochloric  acid  had  nearly 
disappeared,  and  the  quantity  of  organic  acid  in  each 
pint  required  for  saturation  nearly  seventeen  grains 
of  the  alkali.  If,  therefore,  we  ai-e  desirous  of  giving 
relief  we  ought  to  follow  regularly  the  variations 
in  the  character  of  the  acid  in  the  vomited  matters. 
For  this  purpose  the  following  plan  of  procedure  will 
be  found  easy  as  well  as  i-eliable.  The  vomit  is 
poured  into  a  tall  cylindrical  glass  jar,  aiid  allowed  to 
settle.  Of  the  supernatant  fluid  draw  off  100  cc,  or  if 
so  much  cannot  be  obtained,  then  50  cc.  or  25  cc. 
Shake  this  up  with  an  equal  weight  of  ether  in  a 
cylindrical  tube,  set  aside  till  the  ether  has  separated 
from  the  mixture.  Then  remove  etherial  solution  by 
means  of  a  pipette.  Now,  as  it  has  been  stated 
(§  1.34,  page  181),  that  the  organic  acids  are  more 
readily  removable  by  ether  than  the  mineral  acids,  so 
that  the  acidity  of  the  etherial  solution  represents  in 
the  main  the  acidity  due  to  organic  acids,  whilst  the 

*  I  have  endeavoured  to  discriminate  between  the  forms  of 
"  acidity  "  met  with  in  functional  disorders  of  tlie  stomach  by 
reference  to  the  condition  of  the  urine.  (Sec  chaps,  ii.  and  iii., 
"  Morbid  Conditions  of  the  Urine."    Churchill,    18S2.) 


I  go  Clinical  Chemistry.  [Chap.  v. 

acidity  of  the  vomit,  after  extraction  by  ether,  repre- 
sents nearly  the  whole  of  the  mineral  acids  (hydro- 
chloric). If,  therefore,  we  take  the  acidity  of  the 
supernatant  fluid  of  the  vomit  before  agitation  with 
ether,  by  the  same  process  as  directed  for  determining 
the  acidity  of  urine  (§  107,  page  112),  and  again  after- 
wards, we  can  judge  by  the  difference  in  the  acidity 
whether  the  organic  or  mineral  acid  is  in  excess. 
If  the  former,  the  rediiction  in  the  acidity  will  be 
marked  ;  if  the  latter,  it  will  not  be  considerable.  If 
we  desire  to  find  out  what  organic  acids  are  present, 
the  vomit  will  have  to  be  treated  repeatedly  and  suc- 
cessively with  ether  till  the  co-efficient  of  partage  of 
each  has  been  determined.  There  is  no  necessity,  how- 
ever, for  engaging  on  this  lengthy  process  ;  for  clinical 
purposes  it  is  sufficient  to  determine  whether  we  are 
dealing  in  any  given  case  with  excess  of  organic  or 
mineral  (hydrochloric)  acid. 

(2)  Detection  of  poisons  in  'tiomit. — Without 
engaging  in  the  elaborate  and  exact  processes  of 
analysis  requisite  for  toxicological  purposes,  and 
whichj  when  required  for  medico-legal  purposes,  should 
always  be  conducted  by  a  professional  expert,  medical 
men  frequently  have  to  decide,  when  called  to  a  case 
of  urgent  vomiting,  whether  it  is  due  to  a  poisonous 
agent.  In  these  cases  there  is  generally  no  time  to 
refer  the  matter  to  an  analytical  chemist.  Every 
medical  man,  therefore,  ought  to  be  able  to  conduct  a 
preliminary  enquiry,  so  as  to  gain  some  insight  as  to 
the  nature  of  the  case  with  which  he  is  dealing.  As 
a  rule  a  clue  is  afibrded  by  the  chai'acter  of  the 
symptoms,  which  show  whether  the  poison  belongs  to 
the  irritant  class,  or  is  a  corrosive  substance,  or  one  of 
the  vegeto-alkaloids ;  and  we  have  generally  some  of 
the  substance  taken  left,  which  also  inaterially  assists  ; 
thus  we  readily  recognise  oil  of  almonds,  vermin  paste, 
oil  of  vitriol,  oxalic  acid,  and  the  like.     But  where  the 


Chap,  v.]  Vomit.  191 

substance  cannot  be  obtained  for  inspection,  ami  the 
symptoms  are  obscure,  we  are  forced  to  make  an 
elementary  analysis.  The  plan  to  be  adopted  is  as 
follows: — Reserve  a  sufficient  portion  of  the  vomit  for 
detailed  examination  at  the  hands  of  an  expert ;  place 
this  in  a  strong  bottle  tightly  corked  and  sealed.  With 
regard  to  the  surplus  proceed  according  to  the  follow- 
ing method,  which  deals  with  the  most  common  forms 
of  poisoning. 

(a)  Volatile  poisons. — Place  a  small  quantity  of 
the  fluid  in  a  test  tube,  and  gently  warm  the  fluid ;  if 
prussic  acid  is  present,  the  peculiar  odour  Avill  be 
evolved.  The  best  confirmatory  test  for  this  is  to 
l")lace  a  little  of  the  vomit  on  a  small  watch-glass 
or  glass  slide,  and  add,  by  means  of  a  stirring-rod, 
five  or  six  drops  of  strong  sulphuric  acid ;  hold 
over  the  watch-glass  another  moistened  with  liquor 
potasste.  The  fumes  of  the  hydrocyanic  acid  form 
potassium  cyanide.  This  is  tested  by  stirring  it 
with  a  rod  dipped  successively  in  a  solution  of  a 
ferrous  salt,  ferric  salt,  and  hydrochloric  acid,  when, 
if  hydrocyaniG  acid  is  present,  Prussian  blue  will 
be  developed.  If  no  hydrocyanic  acid  be  found, 
apply  strong  heat  to  another  portion  of  the  vomit 
placed  in  a  narrow  tube,  and  cany  the  tube  into 
a  darkened  room  to  see  if  fumes  of  'phosphonus  are 
given  off". 

(6)  (Jorroslve  poisons. — Test  with  litmus  paper;  if 
strongly  acid,  probably  oxalic  acid  (§  47),  sulphuric  acid 
(§  82),  hydrochloric  acid  (§  79),  or  carbolic  acid  (§  50) ; 
if  strongly  alkaline,  due  to  some  of  the  caustic  alkalies 
or  alkaline  salts. 

(c)  Metallic  irritant  poisons. — Some  of  the  vomit, 
acidulated  with  pure  hydrochloric  acid,  is  placed  in  a 
test-tube,  and  a  strip  of  perfectly  clean  copper,  dijjped 
in  alcohol  to  prevent  fatty  matters  adhering  to  it,  is 
then  immersed   in  the  acidulated  mixture,  and  heat 


192  Clinical  Chemistry.  [Chap.  v. 

applied  for  about  twenty  minutes.  If  arsenic,  anti- 
mony, or  mercury  is  present,  the  copper  will  be 
stained  black.  Remove  the  copper  strip,  and  wash  it 
with  a  little  very  dilute  solution  of  ammonia,  and 
then  dry  it  between  folds  of  blotting-paper.  Then 
place  in  a  narrow  glass  tube,  and  proceed  as  directed 
for  the  detection  of  mercury  (§  132),  arsenic  and 
antimony  (§  151). 

Strychnine  and  morphia. — A  small  portion  of  the 
vomit  is  to  be  rendered  strongly  alkaline  with  sodium 
carbonate,  and  agitated  with  four  times  its  volume  of 
ether.  After  the  etherial  solution  has  formed  a  layer 
on  the  surface,  it  is  to  be  removed  by  means  of  a 
pipette,  and  allowed  to  evaporate  spontaneously  in  a 
watch-glass ;  the  residue  is  to  be  examined  for  mor- 
phia (§  70),  strychnia  (§  71).  It  is  often  sufficient 
to  place  a  drop  of  the  etherial  solution  on  the  tongue, 
by  means  of  a  glass  rod,  to  learn  the  character  of 
the  alkaloid.  If  a  frog  can  be  obtained,  evidence 
of  poisoning  by  an  alkaloid  is  then  most  readily 
obtained  by  injecting  some  of  the  ether  extract  under 
the  skin. 

Opium. — Evaporate  a  small  portion  of  the  vomit 
on  a  porcelain  dish ;  touch  the  dry  residue  with  ferric 
chloride  ;  a  cherry -red  colour,  which  does  not  disappear 
when  touched  with  mercuric  chloride,  indicates  the 
presence  of  meconic  acid  (§  83). 

137.  Oases  in  the  stoKBiach< — -The  nature  of 
the  gaseous  contents  of  the  stomach  in  health  and 
disease  will  be  best  considered  with  reference  to  the 
gases  in  the  intestinal  canal  (§  150). 

138.  Bile. — The  composition  of  the  bile  varies 
considerably,  the  proportion  of  its  solid  constituents 
ranging  from  9  to  17  per  cent.,  being  always  most 
after  a  meal.  The  following  analyses,  (1)  made  by 
Frerichs,  is  from  the  bile  taken  from  the  gall-bladder 
of  a  healthy  man  killed  by  an  injury;  (2)  the  mean  of 


Chap,  v.] 


Composition  of  Bile. 


193 


five  analyses  by  Hoppe  Seyler,  obtained  from  bodies 
in  the  post-mortem  room  : — 


No.  1. 

No.  2. 

Frcrichs. 

Hopije  Seyler. 

Water 

Inorganic  salts  .... 

85-92 
•78 

91-68  j 

Organic  matter  .... 

13-30 

8-32 

^lucus  pigment .... 

2-98 

1-29 

Bile  salts 

9-14 

3-90 

Fat 

•92 

0-73 

Soaps           "1 

(  1-39 

Cholesterin  I      .        .        .        . 

•26 

{  0-35 

Lecithin      J 

(0-53 

Obtained  fresh,  as  it  flows  from  the  liver,  it  is  a 
thin,  transparent  fluid,  of  golden-yellow  colour,  like 
yolk  of  egg,  of  a  very  bitter  taste,  of  alkaline  re- 
action, and  an  average  sp.  gr.  of  1-018.  When 
obtained  after  death,  the  colour  is  of  brownish- 
yellow  ;  it  acquires  a  tenacious  consistence  from  the 
presence  of  mucin,  which  is  furnished  by  the  gall- 
ducts  and  gall-bladder.  Bile  mixes  freely  with  oil 
and  fat,  and,  when  shaken  with  them,  forms  an 
emulsion,  which  renders  their  passage  through  animal 
membranes  more  easy.  Added  to  a  solution  of  gastric 
peptones,  a  precipitate  occurs ;  this  precipitate  is 
caused,  no  doubt,  by  the  alkaline  salts  of  the  bile 
precipitating  the  parapeptone  from  its  acid  solution. 
The  quantity  of  bile  secreted  increases  suddenly  after 
a  meal,  reaches  its  maximum  in  about  two  hours,  and 
then  gradually  declines.  The  quantity  of  bile  dis- 
charged daily  may  be  put  at  forty  ounces.  Thus, 
Carpenter,  from  the  experiments  of  Nasse,  Plainer, 
and  Stackman,  calculated  that  a  man  weighing  154- 
pounds  should  secrete  this  quantity  ;  whilst  jNIurchison 

N 


194  Clinical  Chemistry.  [Chap.  v. 

records  (Case  CLXxii.,  Diseases  of  Liver)  an  instance 
where  quite  two  pints  of  bile  were  discharged  daily 
through  a  fistulous  opening  in  the  gall-bladder.  Of 
'  this  quantity,  only  a  small  portion  escapes  by  the 
bowel,  the  remainder  being  re-absorbed  in  the  intes- 
tines. Thus,  the  experiments  of  Bidder  and  Schmidt 
on  dogs  have  shown  that  only  j^^th  of  the  sulphur 
originally  passed  into  tbe  intestine  with  the  bile 
appears  in  tlie  faeces.  Bischoff,  again,  has  calculated 
that  about  46  grms.  of  the  altered  biliary  acids  are 
discharged  by  man  daily  with  his  faeces,  whilst  Voit 
has  shown  that  the  average  daily  quantity  formed  by 
the  liver  amounts  to  170  grms. ;  therefore  124  grms. 
must  be  otherwise  disposed  of.  The  observations  of 
Jalfe  and  McMunn  have  shown  that  the  bilirubin  of 
the  bile  pigment  is  oxydised  in  the  intestine  to  uro- 
bilin, in  which  condition  it  is  absorbed,  and  passes  off 
from  the  body  by  the  kidneys  as  the  chief  colouring 
matter  of  the  urine,  either  as  urobilin  or  its  more 
oxydised  product  choletelin,  only  a  portion  of  the 
biliary  pigment  being  discharged  by  the  intestines 
with  the  fajces.  As  Murchison  pointed  out,  this 
re-absorption  of  bile  is,  in  fact,  merely  part  of  that 
chemical  circulation  which  is  constantly  taking  place 
between  the  fluid  contents  of  the  bowel  and  the  blood, 
the  existence  of  which  has  been  already  alluded  to 
(§  9).  Bile  has  no  action  upon  the  digestion  of  pro- 
teid  substances,  beyond  the  negative  effect  of  preci- 
pitating paraptjptone,  as  noticed  above.  The  bile 
oi  some  animals  has  an  action  on  starch,  converting  it 
into  glucose ;  and  some  observers  state  that,  to  a 
slight  extent,  a  similar  action  occurs  with  quite 
fresh  human  bile.  It  acts,  however,  on  the  fatty 
substances  by  forming  an  emulsion  with  them ;  this 
can  be  seen  by  placing  a  drop  of  cod-liver  oil  on  a 
glass  slide,  and  adding  a  drop  of  fresh  bile,  when  a 
milky  emulsion  will  be  formed.    Owing  to  the  alkaline 


Ch;.|).  v.]  Jaundice.  195 

salts,  bilo  is  capable  of  forming  soaps  with  fatty 
acids.  Experimentally  it  has  been  shown,  after  ap- 
plying a  ligature  to  the  common  duct,  that  an 
animal  absorbed  less  fat  than  before.  It  has  also 
been  pointed  out  that,  where  biliary  fistulse  have  been 
established  for  a  consideral)le  time,  nutrition  was 
only  kept  up  so  long  as  the  loss  was  compensated  by 
increased  food.  Bile  acts  as  a  natural  purgative,  by 
Ktimulating  peristalsis  ;  and,  since  it  possesses  powerful 
antiseptic  properties,  it  arrests  putrefactive  fermenta- 
tion in  the  intestines.  A  defective  secretion  of  bile, 
therefore,  is  one  of  the  chief  causes  of  flatulent 
dyspepsia.  In  my  work  on  "  Morbid  Conditions  of 
the  Urine  associated  with  Derangements  of  Diges- 
tion"  (p.  49),  1  have  pointed  out  that  the  form  of 
dys])cpsia  ai'ising  from  deficient  secretion  of  bile  is 
frequently  attended  with  an  alkaline  condition  of 
urine,  since  the  bile,  being  the  chief  secretion  by 
which  the  alkaline  salts  are  discharged  from  the 
blood,  any  hindrance,  therefore,  to  the  discharge  of 
the  bile  leads  to  their  being  eliminated  in  greater 
quantity  by  the  kidney.  It  is  in  this  form  of 
dyspepsia  that  the  greatest  good  is  obtained  by  tlie 
administration  of  dilute  hydrochloric  acid.  Dr.  Wick- 
ham  Legg  is  of  opinion  that  the  passage  of  bile  into 
the  intestine  appears  in  some  way  necessary  to  the 
formation  of  glycogen  by  the  liver,  since,  after  liga- 
ture of  the  bile-duct  of  a  cat,  the  diabetic  puncture 
failed  to  give  rise  to  sugar  in  the  urine.  In  jaundice, 
a  yellow  tingeing  of  the  skin,  as  well  as  the  other 
tissues  and  fluids,  takes  place,  owing  to  the  presence 
of  biliary  matters  in  the  circulation.  Jaundice  is  gene- 
rally considered  as  being  either  iLeptof/enous,  caused 
l)y  re-absorption  of  bile  either  fi'om  obsti'uction  of  the 
bile-ducts  or  from  disturbances  of  the  portal  cii'cu- 
lation,  and  hcematoyenous,  from  changes  occurring  in 
the  blood.      Among  the  causes  leading  to  heptoyenous 


196  Clinical  Chemistry.  [Chap.  v. 

jaundice  are,  (1)  simple  catarrh  of  the  bile -ducts, 
either  by  a  mucus  plug  in  the  gall  duct  or  by  swelling 
of  the  mucous  fold  over  the  orifice  of  the  duodenum, 
accompanied  with  gastro-intestinal  catarrh,  as  is  seen 
in  malarial  fever,  secondary  syphilis,  pyaemia,  etc. ; 
(2)  direct  obstruction  of  the  ducts,  as  by  impaction  of 
gall  stones  or  the  presence  of  tumours ;  (S)  sudden 
changes  of  blood  pressure,  as  haemorrhage  from  the  roots 
of  portal  veins,  which  favours  the  imbibition  into  the 
circulation  of  the  secreted  bile.  The  icterus  menstrualis, 
and  the  jaundice  so  often  observed  in  pneumonia  of 
the  right  lung,  are  probably  caused  by  the  alteration 
of  the  blood  pressure  in  the  portal  system. 

IIce.matogenous  jaundice  is  accounted  for  :  (a)  That 
when  the  destruction  of  liver  tissue  is  extensive,  the 
pigments  of  the  bile  are  formed  in  the  blood,  (h)  That 
the  bile  pigment  in  these  cases  is  obtained  by  the  disso- 
lution of  the  blood  corpuscles,  and  by  the  conversion 
of  the  haemoglobin  into  bile  pigment.  Among  the 
forms  of  jaundice,  of  haematogenous  origin,  are  the 
jaundice  of  acute  yellow  atrophy,  phosphorus  poisoning, 
typhus,  pyaemia,  and  septicaemia,  and  the  jaundice  fol- 
lowing the  bites  of  venomous  animals.  With  regard  to 
the  theories  supported  in  advance  of  a  true  haemato- 
genous jaundice,  it  will  be  sufficient  to  say,  with  regard 
to  the  view  that  jaundice  arises  when  the  liver  is  exten- 
sively destroyed,  by  the  accumulation  of  the  bile  pig- 
ment in  the  blood,  that  physiology  has  long  since  dis- 
posed of  the  view  that  the  biliary  elements  are  pre- 
formed in  the  blood ;  they  are  only  elaborated  by  the 
liver.  With  respect  to  the  statement  that  the  jaundice 
in  these  cases  is  due  to  dissolution  of  the  blood  cor- 
puscles and  the  conversion  of  the  haemoglobin  into  bile 
pigments,  experiment  has  sho'^n  that  a  variety  of 
different  substances,  possessing  quite  a  diverse  character, 
introduced  into  the  circulation,  such  as  water,  bile 
acids  J  ether,  chloroform,  etc.,  have  the  power  of  causing 


ch.ip.  v.]  Jaundice.  197 

bile  pigment  to  appear  in  tlic  uriiiP  ;  but  that  is  quite 
a  din'eront  matter  to  converting  liivnioglobin  into  bile 
])ignu'nt  in  tlio  circulatic^n  witlioiit  the  intervention  of 
the  liver.  If  dissolution  of  the  blood  corpuscles,  and 
the  conversion  of  the  ha'niof,dobin  into  bile  pi^nnent 
was,  as  the  propounders  of  this  theor.y  maintain,  the 
cause  of  ha>matogenous  jaundice,  then  scurvy,  in  which 
the  dissolution  of  the  blood  coipuscles  is  carried  to 
a  great  extent,  would  be  invariably  associated  with 
jaundice,  which,  however,  is  rarely  the  case.  In  that 
obscure  disease  ha^matinnria  (§  120,  page  161),  where 
the  colouring  matter  of  the  blood  appears  in  the  urine 
freed  from  the  corpuscles,  jaundice,  though  generally 
present,  is  only  slight,  certainly  not  what  would  be 
expected  with  such  extensive  destruction  of  blood 
corpuscles.  Indeed,  it  is  j^robable  that  hajniatinuria 
depends  rather  on  some  functional  disturbance  of  the 
liver,  by  which  the  effete  haemoglobin  is  not  re- 
duced to  luematiii,  and  froju  ha-matin  to  bilirubin, 
as  a  failure  of  a  normal  process,  than  from  any 
positive  evidence  that  the  dissolution  of  the  l;lood 
corpuscles  is  caused  by  the  introduction  of  a  toxic 
agent  into  the  blood.  Moreover,  in  addition  to  the 
objections  above  urged  to  the  existence  of  an  ha?ma- 
togenous  jaundice,  the  oj)inion  is  gaining  ground  that 
in  the  cases  where  it  is  said  to  occur  there  exists  some 
overlooked  catarrh  in  the  capillary  system  of  gall  ducts, 
and  so  that  the  jaundice  is  really  lieptogenous.  The 
microscopic  examination  of  the  livers  of  dogs  poisoned 
with  phosphorus  has  shown  incontestably  that  the  finer 
ducts  were  plugged  with  a  colourless  mucus  ;  and  when 
we  reflect  how  readily  the  bile  has  been  shown,  experi- 
mentally, to  pass  into  the  circulation  on  the  slightest 
increase  of  excretory  pressure,  we  can  conceive  how  a 
very  slight  exudation  in  the  liner  tubes  may  cause  very 
appreciable  jaundice,  although  the  obstruction  of  the 
tubes  may  not  be  visible  to  the  naked  eye.    Lastly,  the 


198  Clinical  Chemistry,  [Chap.  v. 

supporters  of  tlie  hsematogenous  theoiy  have  long- held 
the  view  that  in  these  cases  the  bile  acids  are  not 
found  in  the  urine,  yet  in  the  jaundice  associated  with 
pyaemia  and  septicaemia,  which  is  one  of  their  strongest 
instances  of  a  jaundice  arising  from  blood  poisoning, 
the  presence  of, the  biliary  acids  in  the  urine  has  been 
repeatedly  demonstrated.  The  position  I  would  take 
with  regard  to  the  existence  of  a  hsematogenous 
jaundice  is  this,  that  there  is  a  form  of  jaundice  arising 
from  a  primary  morbid  condition  of  the  blood,  which 
leads  to  catarrh  of  the  finer  hepatic  ducts,  and  so 
causes  jaundice  from  re-absorption  of  bile  already 
formed  by  the  liver  cells,  and  that  the  jaundice  is  not 
occasioned  by  the  conversion  of  haemoglobin  into  bile 
pigment  in  the  circulation.  With  this  proviso  it 
is  convenient  to  retain  the  term  haematogenons  as 
distinguishing  between  the  forms  of  jaundice  arising 
from  primary  changes,  occurring  in  the  condition  of 
the  blood,  leading  to  catarrh  of  the  finer  biliaiy  ducts, 
as  apart  from  the  jaundice  arising  directly  (hepto- 
genous)  from  obstruction. 

The  analysis  of  bile  is  conducted  as  follows.  The 
specific  gravity  is  taken  by  means  of  the  specific 
gravity  bottle  (§  92),  and  the  degree  of  alkalinity  of 
the  secretion  by  the  process,  and  with  the  same 
standard  solution  as  described  in  determining  the 
alkalinity  of  blood  (§  93). 

139.  The  miicin  is  then  to  be  removed  by  pre- 
cipitation with  alcohol  or  acetic  acid.  On  the  addition 
of  either  of  these  to  bile,  stringy  ropes  of  mucin  are 
formed.  These  must  be  allowed  to  subside,  and  the  bile 
thus  clarified  decanted  oflT  and  passed  through  a  fine 
muslin  filter.  This  is  divided  into  two  portions  {a) 
evaporated  at  a  gentle  heat  to  one-fourth  its  bulk. 
This  forms  inspissated  bile  extract,  (b)  Evaporated  to 
half  its  bulk,  mixed  with  an  equal  quantity  of  animal 
charcoal,  and  introduced  into  a  flask  containing  twice 


Chnp.  v.]  Bile  Pigments.  199 

its  bulk  of  alcohol,  it  is  digostod  till  wanted.  This 
furnis  alcoItoJic  bile  extract.  Tlu-  stiiiifjy  ropes  of  mucin 
are  then  collected  in  a  flask,  and  shaken  up  Avith  other 
to  free  them  from  fatty  matters,  and  afterwards  washed 
■with  water.  When  quite  pure  from  adherinc;  impuri- 
ties, dissolve  in  a  sulHciency  of  lime  or  baryta  water, 
filter  several  times  through  animal  charcoal  to  remove 
any  colouring;  matter  of  the  bile.  Tests  for  mucin, 
§26. 

140.  Bile  pijfmoiifs  are  obtained  for  examina- 
tion from  the  inspissated  bile  extract  or  from  gall 
stones.  The  chief  pigment,  hilimhin,  can  be  obtained 
from  either  of  the  above-named  by  extracting  succes- 
sively with  water,  alcohol,  dilute  hydrochloric  acid, 
boiling  alcohol,  and  ether.  Then  boil  the  dry  residue 
with  pure  chloroform,  and  distil  the  chloroform  extract 
to  near  dryness,  and  then  add  seA^eral  volumes  of 
absolute  alcohol ;  set  aside  for  twenty-four  hours,  when 
an  orange-red  powder  mixed  with  a  few  bluish-brown 
crystals  will  deposit.  Bilirubin  is  insoluble  in  water 
and  ether,  slightly  soluble  in  alcohol,  but  soluble  in 
chloroform,  turpentine,  and  benzol.  On  the  addition 
of  alkalies  to  a  chloroformic  solution  of  bilirubin  it 
lo-ses  its  orange-red  colour.  On  passing  a  current  of  air 
through  an  alkaline  solution  of  bilirubin,  hiliverdin 
is  formed,  which  is  deposited  in  green  flocks  on  the 
addition  of  hydrochloi'ic  acid.  BUifuscin  is  another 
pigment,  which  can  be  obtained  directly  from  the  bile 
by  evaporating  a  chloroform  solution  to  dryness,  dis- 
solving the  residue  in  alcohol,  again  evaporating,  and 
shaking  up  the  residue  with  ether  and  chloroform, 
separating  the  insoluble  portion  by  filtration,  and  dis- 
solving it  in  absolute  alcohol,  from  which  bilifuscin 
is  precipitated  in  brown  flocks  on  the  addition  of 
hydrochloric  acid.  These  flocks  are  soluble  in  alcohol 
and  alkalies,  but  insoluble  in  water,  ether,  and  chloro- 
form.      According  to  Stiideler,  both   biliverdin    and 


200  Clinical  Chemistry.  [Chap.  v. 

bilifuscin  are  formed  from  bilirubin  by  the  assump- 
tion of  water,  thus  : 

Bilirubin.  Biliverdin. 

C,eHi3N,03  +  H,0  +  0=  CieH^N.Og 

Bilii-ubin.  Bilifuscin, 

Although  none  of  the  bile  pigments  mentioned  above 
give  any  spectrum,  there  are  other  colouring  matters 
got  from  bile  by  treatment  with  stronger  reagents  than 
those  required  for  the  separation  of  bilirubin,  bili- 
verdin, and  bilifuscin.  Thus,  by  passing  nitrous 
vapours  into  an  alcoholic  solution  of  bilirubin  a  final 
product  of  oxydation  is  obtained,  which  has  been 
named  clioletelin.*  By  pouring  the  alcoholic  solution 
into  water  after  being  thus  treated,  nearly  all  the 
colouring  matter  separates  in  the  form  of  flakes,  which 
dry  up  to  a  brown  powder,  which  is  soluble  in  alcohol, 
ether,  and  chloroform.  It  gives  no  play  of  colour  with 
nitric  acid,  but  it  yields  a  constant  spectrum,  which,  in 
an  acid  solution,  gives  one  broad  band,  extending  from 
6  to  a  little  beyond  p.  In  alkaline  solutions  the  band 
is  less  ref  rangilole.  Jafie  also  isolated  a  pigment,  which 
gives  the  band  at  F,  to  which  he  gave  the  name  of 
urobilin.  E.  Maly  [Ann.  Chem.  Pliarm.,  clxi.  368, 
clxiii.  77),  by  dissolving  bilirubin  in  dilute  soda  or 
potash  ley,  and  adding  sodium  amalgam,  the  air  being 
excluded,  no  hydrogen  was  given  off,  but  the  dark 
colour  gradually  lightened,  and  after  two  or  three 
days'  action  the  solution  acquired  a  yellow  or  bright 
yellow  colour,  and  then  gave  off  hydrogen.  From 
this  liquid,  hydrochloric  acid  separated  a  pigment, 
which  gave  a  spectrum  identical  with  that  of  Jaffe's 

*  In  the  following  I  have  adopted  MacMunn's  account  of  this 
intricate  and  still  obsctire  subject.  "  The  Spectroscope  in  Medi- 
cine," p.  151.     ChurchiU.     1880. 


Chap.  V.)  Bile  Pigments.  201 

urobilin.  Recent  investigations  seem  to  point  to  the 
conclusion  that  cholctelin  is  the  final  oxydation  product 
of  bilirulnn,  and  that  urobilin  is  an  intermediate  stage  ; 
and  that  while  urobilin  may  appear  in  the  urine,  still, 
under  normal  circumstances,  the  ])igment  that  appears 
in  the  urine  is  cholctelin,  though  it  may  be  absent  in 
disease.  In  addition  to  urobilin  or  choletelin,  Stokvis 
{N.  Rep.  Pluirm.,  xxi,  123)  has  described  another 
reducible  product  of  the  oxydation  of  bile  pigment, 
which  is  formed  as  a  secondary  product,  in  most  cases, 
of  the  oxydation  of  biliary  colouring  matter,  whereby 
Gmelin's  reaction  is  produced  (§  120).  It  is  colour- 
less, or  of  a  light  yellow  tint,  soluble  in  water,  alcohol, 
and  dilute  acids.  It  differs  from  the  bile  colouring 
matter,  and  other  oxydation  products,  in  being  insoluble 
in  ether  and  chloi'oform,  and  not  forming  insoluble 
compounds  with  neutral  or  basic  lead  acetate.  When 
boiled  with  reducing  agents  in  alkaline  solutions  this 
pigment  yields  a  beautiful  rose  red,  wdiich  gives  in  the 
spectrum  a  broad  band  in  gi'een.  In  thick  strata  the 
band  begins  close  to  d  and  extends  to  6  ;  in  thin  strata 
or  dilute  solutions  it  occupies  only  two-thirds  of  the 
'  distance  between  D  and  E,  ending  short  of  E.  This 
pigment  does  not  exist  in  fresh  bile,  and  it  is  not  found 
in  healthy  urine.  MacMunn  thinks  that  the  appearance 
of  the  band  of  this  pigment  in  the  spectrum  of  the 
urine  indicates  grave  disturbance  of  the  system,  as  it 
appears  only  in  those  cases  where  there  is  undoubted 
disease  of  a  severe  character.  With  regard  to  the 
connection  between  the  colouring  matters  of  the  blood, 
bile,  and  urine,  it  is  now  generally  held  that  the  effete 
hsemoglobin  is  reduced  in  the  liver  to  hiematin  and  bili- 
rubin, that  a  portion  of  the  latter  is  passed  out  of  the 
body  with  the  fseces,  but  that  another  portion  is  con- 
verted into  urobilin  in  the  small  intestine,  and  is 
reabsorbed,  and  by  further  oxydation  is  converted  into 
choletelin.      The  view  that  hcematoidin  and  bilirubin 


202  Clinical  Chemistr  y.  [Chap.  v. 

are  identical  is  still  open  to  qtiestion.  tliongli  I  think 
,  tlie  balance  of  e^"idenee  at  present  rather  inclines  to  it. 
To  demonstrate  the  presence  of  bile  pigment  in  any  of 
the  secretions  recourse  is  had  to  Gnielin's  reaction.  This 
consists  in  slowlv  mixing  (^§  li!0)  a  few  drops  of  nitric 
acid,  containing  traces  of  nitrons  acid,  "with  the  stis- 
pected  fluid,  vrhen  a  play  of  colours  Trill  be  observed, 
of  -which  green  is  alone  characteristic  of  the  bile 
piigment.  If  Tve  examine  this  reaction  by  means  of 
the  spectroscope,  "sve  find  the  solution  gives  a  broad 
shading  in  orange  and  yelloTv,  and  a  broad  band  at  F. 
As  the  osydation  proceeds,  the  shading  in  orange  and 
yello-w  clears  up,  leavins;  only  the  band  in  F,  the 
spectrum  of  urobilin. 

111.  Bile  acid$. — The  method  for  obtaining  the 
bile  acids  from  urine  has  been  described  §  lilO.  To 
obtain  them  from  bile  "we  add  excess  of  alcohol  to  the 
alcoholic  extract  of  bile,  and  filter.  The  precipitate  is 
dissolved  in  •w-ater.  and  the  aqueous  solution  precipi- 
tated -with  neutral  lead  acetate.  The  precipitate  is 
removed,  -washed,  dissolved  in  alcohol,  and  the  lead 
removed  by  precipitation  -w-ith  sulphydric  acid.  The 
clear  filtrate  on  standing  -will  deposit  crystals  of* 
gJycochoUc  acid  (§  53).  The  mother  liquor  left  after 
the  removal  of  glycochoKc  acid  is  precipitated -with  basic 
lead  acetate,  and  the  precipitate  treated  in  the  same 
■way  as  directed  for  glycocholic  acid,  -when  taurocholic 
acid  -will  separate  out  as  oily  resinous  drops  (§  54). 
Both  bile  acids  give  a  purple  reaction  (Pettenkofter's 
test)  -when  mixed  -with  strong  sulphuric  acid  and 
glucose.  The  best  method  of  carrying  otit  the  test 
is  described  §  120.  The  spectrum  of  Pettenkofier's 
test,  according  to  ]\IacMunn,  gives  a  band  outside  D, 
and  broad  band  at  e.  Heynsius  and  Campbell,  ho-w- 
ever,  give  the  spectrum  of  sodium  taurocholate  -with 
sulphtiric  acid  and  sttgar,  as  represented  by  three  bands, 
one  bet-ween   c  and  D,  the  next  bet-«"een  D   and  E, 


Chap.  V.)  Bile  Acids.  203 

and  the  thii-d  near  F  (Pfls^er's  Archxv.  f.  Pht/s.,  iv., 
407).  Tlio  bile  acids  ai'e  furnished  by  the  nietaWlism 
of  the  albuminous  constituents  ;  but  whether  directly 
from  tlie  s^»litting  up  of  the  pej)tones,  as  Dr.  Wiekhain 
Legg  considei^s  probable,  seeing  the  great  dependence 
of  the  bile-making  functions  on  the  glycogenetic  func- 
tion ;  or,  as  seems  to  me  more  likely,  from  the  breaking 
up  of  the  ertete  albuminous  matters  of  the  body  in  the 
liver,  is  doubtful  A  portion  of  the  bile  acids  (chietly 
the  taurochloric  acid)  passes  off  by  the  bowels  with  the 
fivces,  jvirtly  unaltered,  partly  broken  up  into  taurin, 
cholic  acid,  and  dyslysin.  A  portion,  chietly  the  glyco- 
cholic  acid,  is  absorbed  by  the  intestine.  An  experi- 
ment of  Tappeiner  ( Wiener  Sitzgsber,  Bd.  cxxA-ii. 
187S,  iii.  abth)  has  shown  that  this  absorption  oecure 
in  the  jejunum  and  ileum,  and  not  in  the  duodenum. 
Of  the  portion  thus  absorbed  the  ultimate  fate  is 
unknown.  A  trace  probably  passes  off  with  the  urine 
even  in  health,  since  Xaunyn  and  Draggendorf  have 
proved  the  presence  of  bile  acids  in  non-jaundiced 
urine,  whilst  some  portion  of  the  taurocohlic  acid  is 
probably  oxydised,  and  furnishes  the  partially  oxydised 
sulphur  product  originally  observed  in  the  urine  by 
Ronalds,  and  which,  in  minute  quantities,  is  always 
pi-esent  in  nonnal  urine  (§  114).  Injection  of  the  bile 
acids  into  the  blood  produces  very  detinite  results.  It 
destroys  the  red  blood-coi-puscles ;  if  a  few  drops  of 
solution  of  bile  acids  are  placed  on  a  glass  slide,  and  a 
drop  of  blood  be  added,  no  trace  of  blood  corpuscles 
will  be  found  on  microscopic  examination.  Taurocholic 
acid  seems  to  possess  this  property  in  even  a  higher 
degree  than  glycocholic  acid.  Bile  acids,  when  injected, 
cause  rapid  parenchymatous  degenei-ation  of  the  glands 
and  muscles.  Their  action  on  the  heart  is  very  marked, 
causing  slowing  of  the  pulse.  This  phenomenon. 
Dr.  ^Viokham  Legg  (Proc.  Poi/al  Soc.,  vol.  xxiv.,  p. 
•i-42  ;  1S7G)  thinks  is  not  due  to  any  influence  tlirough 


204  Clinical  Chemistry.  [Chap. v. 

the  vagi,  or  direct  action  on  the  muscular  walls,  but 
by  their  influence  on  the  ganglia  of  the  heart.  Steiner 
has  confirmed  Dr;  Legg's  view  ;  but  he  thinks  that  bile 
acts  upon  only  one  of  the  cardiac  ganglia,  since  he  found 
that  by  letting  a  drop  of  bile  fall  upon  the  back  of  a 
frog's  heart  there  was  at  once  a  cessation  of  the  heart's 
beat,  whilst  if  it  was  placed  on  the  fore  surface  of  the 
heart  no  change  in  the  pulse  took  place  for  some  time. 
Injection  of  bile  acids  also  produces  a  peculiar  spasm 
of  the  respiratory  muscles,  and  the  diaphragm  remains 
in  a  state  of  deep  inspiration.  They  are  said  to  lower 
the  bodily  temperature.  The  urine  after  injection  of 
bile  acids  becomes  dark-coloured,  often  with  traces  of 
albumin,  casts,  and  granules,  but  no  blood  corpuscles. 
Frerichs  considered  the  dark  colour  due  to  the  con- 
version of  the  bile  acids  into  bile  pigment.  Kiihne 
attributes  it  to  the  destruction  of  the  blood  corpuscles 
by  the  bile  acids  acting  on  the  haemoglobin ;  but  Dr. 
Wickham  Legg  has  been  unable  to  satisfy  himself  of 
the  presence  of  pigment,  in  many  observations  on 
rabbits,  and  is  inclined  to  believe  the  difference  iu 
observation  depends  on  the  animal  experimented  on, 
since  dog's  urine  often  gives  the  reaction  (Gmelin's) 
for  bile  pigment,  even  when  the  animals  are  supposed 
to  be  in  perfect  health.  Many  physicians  have  been 
led  to  regard  the  presence  or  absence  of  bile  acids  as  a 
diagnostic  point,  deciding  whether  the  jaundice  was 
heptogenous  or  hsematogenous  in  character.  In  the 
former,  it  was  said  they  were  present,  in  the  latter 
absent.  No  such  definite  conclusion,  however,  is  war- 
ranted from  the  facts  before  us.  Traces  of  bile  acids 
are  to  be  found  in  normal  urines  ;  the  amount  is 
increased  in  all  forms  of  jaundice,  especially  at  their 
onset.  In  cases  due  to  obstruction,  without  great 
destruction  of  liver  tissue,  they  are  often,  especially  at 
first,  considerably  increased,  gradually  declining  in 
amount  as  the  case  goes  on,  till  they  often  cease  to 


Chnp. V.)  Fattv  Matters  of  Bile.  205 

appear.  In  jaundice,  with  destruction  of  the  liver 
tissue,  as  in  acute  yellow  atrophy,  hepatic  abscess, 
rapidly  growing  cancer,  they  are  present  at  first,  but 
as  the  liver  tissue  becomes  destroyed  they  disappear. 
Their  presence  or  absence,  therefore,  does  not  dis- 
tinguish between  the  nature  of  the  jaundice,  but  only 
shows  the  stage  which  it  has  reached. 

142.  Fats  which  consist  of  cholesteiin,  saponi- 
fiable  fats,  and  lecithin  are  to  be  separated  and  deter- 
mined as  directed  for  blood  (§  99).  With  regard  to 
cholesterin,  the  chief  fatty  constituent  of  the  bile,  it 
is  doubtful  whether  it  should  be  regarded  as  formed  in 
the  liver,  or  is  merely  excreted  from  the  blood.  The 
latter  view  has  been  generally  adopted,  partly  in  con- 
sequence of  Dr.  Flint's  views  with  regard  to  the 
supposed  toxic  influence  this  body  has  when  its 
excretion  is  obstructed,  giving  rise  to  a  condition  he 
calls  cholesteraemia.  The  reasons  against  accepting 
his  views  have  been  enumerated  when  considering  the 
toxic  conditions  of  the  blood  (§102).  I  am  disposed 
to  think  that  cholesterin  is  formed  in  the  liver  as  well 
as  in  the  brain,  nervous  system,  etc.,  and  that  it  is 
not  an  excretory  product,  properly  so  called,  and  that 
it  fulfils  a  definite  purpose  in  the  organism  ;  that  it  is 
not  excreted  by  the  liver,  but  that  some  of  the 
cholesterin  formed  in  the  organ  is  secreted  with  the 
bile.  Cholesterin,  mixed  with  bile  pigment,  is  also 
the  chief  constituent  of  biliary  calculi.  Eor  chemical 
reactions  of  cholesterin,  see  §  51, 

143.  Salts. — The  inspissated  bile  extract  is  to  be 
incinerated,  and  the  estimation  of  the  acids  and 
bases  made  as  dii-ected  for  blood  (§  101).  The  chief 
base  is  soda,  in  combination  with  the  bile  acids,  and 
which  will  in  the  incinerated  residue  be  found  aa 
a  carbonate.  Sodium  chloride  is  also  abundant,  and 
sodium  phosphate  ;  then  comes  phosphate  of  lime  and 
magnesia  and  chloride  of  pota,ssium.     Traces  of  iron 


2o6  Clinical  Chemistry.  [Chap.  v. 

are  always  present,  and  are  said  to  be  increased  when 
this  metal  is  taken  as  medicine.  Minute  traces  of 
silica,  and  also  copper,  are  stated  on  good  authority 
to  be  constantly  present. 

144.  Biliary  calculi  will  be  considered  in 
chapter  vi.,  in  the  section  referring  to  morbid  con- 
cretions. 

145.  Functional  d.eraug'enients  of  the 
liver. — In  addition  to  the  formation  of  bile,  the 
iiver  performs  two  other  important  functions,  viz., 
(1)  the  formation  of  glycogen;  and  (2)  the  meta- 
bolism of  certain  albuminous  constituents  of  the 
body.  To  these  may  be  probably  added  another, 
consisting  of  certain  synthetical  processes,  by  which 
the  carbohydrates  are  converted  into  fats,  and  the 
peptones  transformed  into  albumins  prior  to  absorp- 
tion into  the  blood  by  a  process  of  deliydration 
(§1.35). 

(1)  Glycogenic,  function. — Diabetes. — Although  the 
formation  of  glycogen  is  not  restricted  to  the  liver, 
since  it  has  been  found  in  small  quantities  in  other 
tissues,  still,  undoubtedly,  it  is  the  chief  seat  of  its 
formation.  The  only  exception  to  this  statement  is 
during  the  first  period  of  intra-uterine  life,  when  the 
liver  is  found  free  from  this  substance,  whilst  sugar  is 
found  in  the  fluid  of  the  allantois  and  liquor  amnii. 
During  the  latter  period,  however,  of  gestation  the 
liver  of  the  foetus  contains  glycogen,  and  sugar  dis- 
appears from  these  fluids.*  It  has  also  been  found 
in  the  pulmonary  tissues  of  hybernating  animals. 
In  the  consolidated  lung  of  pneumonia,  and  in  muscles 
v/hich  have  been  kept  long  at  rest,  the  quantity  is 
increased.  With  the  resumption  of  activity,  the 
glycogen  in  the  first  case  disappears,  in  the  second 

*  In  the  liquor  amnii  of  a  diabetic  patient,  recently  confined, 
which  Dr.  .John  Williams  brought  to  me  for  examination,  no  trace 
of  sugar  could  be  found. 


Chap,  v.]  Diabetes.  207 

cliiuiui.slies  in  quantity.  Dr.  Pavy  has  very  ingeniously 
brought  forward  these  facts  to  show  that  venous  blood 
is  favourable,  and  oxygenated  blood  is  unfavourable,  to 
its  accumulation  ;  and,  since  there  is  no  organ  in  the 
body  su2)])lied  with  venous  blood  in  like  manner  to  the 
liver,  so,  in  correspondence,  nowliere  does  glycogen 
exist  to  a  like  extent.  In  early  fcctal  life,  however, 
the  supply  of  venous  blood  to  the  liver  from  the 
chylopoictic  viscera  is  quite  insignificant  compared 
with  the  oxygenated  l)lood  received  from  the  um- 
bilical vein,  and  so  glycogen  does  not  accumulate. 
As  ftutal  life  advances  this  relationship  becomes 
altered.  In  hybernatmg  animals,  and  in  muscles  at 
rest,  a  reduced  supply  of  arterial  blood  also  must 
necessarily  prevail.  Dr.  Pavy  has,  moreover,  pointed 
out  that  in  the  consolidated  lung,  owing  to  its  im- 
perviousness  to  air,  the  venous  blood  of  the  pul- 
monary artery  does  not  become  oxygenated,  but 
retains  its  venous  character,  and  thus  stands  in  the 
same  position  as  the  portal  blood  does  to  the  liver.  It 
is  important  to  bear  these  facts  in  mind  with  regard 
to  the  origin  of  diabetes ;  for,  if  a  limited  supply  of 
oxygenated  blood  is  favourable  to  the  accumulation  of 
glycogen,  it  is  reasonable  to  suppose,  if  the  opposite 
condition  be  ^^I'Psent,  and  oxygenated  or  imperfectly 
de-arterialised  blood  be  passed  to  the  liver  through  the 
■poi'tal  vein,  rapid  transformation  of  its  amyloid  sub- 
stance into  sugar  will  be  accomplished,  and  glycosuria 
be  the  result.  And  this  brings  us  to  the  question, 
what  is  the  fate  of  the  glycogen  formed  in  the  liver 
under  normal  conditions'?  The  view  originally  sug- 
gested by  Bernard,  and  generally  accepted  by  the 
profession,  was  that  the  glycogen  was  immediately 
converted  into  sugar,  and  this,  on  reaching  the  general 
circulation,  was  destroyed,  the  destruction  occurring 
chiefly  in  the  perii)heral  capillaries  and  in  the  nmscles, 
leading  to  the  increased  production  of  carbonic  acid 


2o8    ,  Clinical  Chemistry.  [Chap.  v. 

and  water.  Dr.  Pavy,  on  the  other  hand,  maintains 
that  the  liver  is  essentially  a  sugar-assimilating,  in- 
stead of  a  sugar-forming,  organ^  and,  when  its  assimi- 
lative action  is  properly  exerted,  so  little  sugar  is 
allowed  to  pass  into  the  general  circulation  that  the 
quantity  existing  in  arterial  blood  is  insufficient  to 
allow  more  than  a  mere  trace  to  appear  in  normal 
urine.  The  glycogen  is  stored  up  in  the  liver  cells, 
where  it  presumably  undergoes  a  change  which  forms 
one  of  the  links  in  the  series  leading  up  to  the  final 
issue ;  viz.,  the  utilisation  of  sugar  as  a  force-pro- 
ducing agent. 

Now,  according  to  Bernard's  view,  diabetes 
would  depend  on  excessive  formation  of  glycogen 
in  the  liver,  by  which  an  excessive  amount  of  sugar, 
over  and  above  its  power  of  reduction  into  carbonic 
acid  and  water,  would  reach  the  circulation.  Whilst, 
according  to  Dr.  Pavy's  view,  diabetes  is  -due  to  a 
failure  of  the  assimilative  function  of  the  liver, 
which,  instead  of  storing  up  glycogen^  allows  it  to 
pass  off  as  sugar,  and,  in  proportion  as  it  does  so,  the 
uriiie  acquires  a  more  or  less  marked  saccharine 
character.  Now,  to  return  to  the  fact  that  excess  of 
venous  blood  is  favourable  to  the  storing-up  of  gly- 
cogen, whilst  oxygenated  blood  causes  its  disappear- 
ance. Dr.  Pavy  (Proc.  Royal  Soc.,^\me  and  Nov.,  1875) 
has  shown  that,  by  introducing  defibrinated  arterial 
blood  into  the  portal  system,  strongly-marked  glyco- 
suria was  quickly  introduced ;  and  he  also  established 
the  negative  by  employing  defibrinated  venous  blood; 
that  is  to  say,  the  glycosuria  was  due  to  the  influence  of 
the  oxygenated  blood,  and  not  to  any  other  part  of 
the  operation.  This  experiment  shows  that  oxygenated 
blood  reaching  the  liver  through  the  portal  vein  is 
perversive  of  the  proper  action  and  instrumental  in 
producing  glycosuria.  Dr.  Pavy  also  induced  glyco- 
suria   (11  grains    of   sugar   to    1    oz.    of    urine)    by 


chnp.  v.]  Diabetes.  •   209 

artificial  respiration ;  and  Titfcnbach  has  similarly 
succeeded  in  obtaining  sugar  in  urine  in  curarised 
rabbits. 

But  in  what  manner  in  diabetes  is  the  liver  thus 
nnduly  charged  with  oxygen  i-eaching  the  liver  by  the 
poi'tal  vein  ?  Dr.  Pavy  considers  that  the  state 
into  which  the  portal  blood  is  thrown  by  vaso- 
motor paralysis  aflecting  the  vessels  of  the  chylo- 
poietic  viscera,  is  the  key  to  the  explanation  of  the 
saccharine  condition  of  the  urine  in  diabetes.  He 
says,  "It  may  be  observed  in  the  case  of  division  of 
the  sympathetic  in  the  neck,  that  not  only  is  there  a 
hyperpemic  condition  of  the  ear,  but  that  the  veins 
contain  much  redder  blood  than  natural.  In  fact,  the 
blood  passes  with  such  velocity  and  in  such  volume 
through  the  aflected  part  that  it  does  not  become  de- 
artei-ialised.  A  similar  state  existing  in  connection 
with  the  vessels  of  the  chylojDoietic  viscera  will  give 
what  is  sufhcient  to  produce  glycosuria.  Without  any 
new  agent  being  brought  into  question,  the  simple 
passage  of  blood  through  the  vessels  in  such  a  mannef 
as  to  cause  it  to  arrive  in  the  portal  vein  in  an  im- 
perfectly de-arterialised  condition  will  supply  all  that 
is  wanted  to  account  for  the  unnatural  passage  of 
sugar.  In  the  vaso-motor  paralysis,  which,  observation 
shows,  is  produced  by  lesions  of  the  nervous  system 
that  give  rise  to  glycosuria,  we  have  a  condition  that 
leads  to  the  presence  of  imperfectly  de-arterialised 
blood  in  the  portal  vein,  and  in  this  condition  of  imper- 
fectly de-arterialised  blood  in  the  portal  vein  we  have 
a  circumstance  that  suffices  to  determine  the  escape  of 
sugar  from  the  liver  in  a  manner  to  produce  a  diabetic 
state  of  the  urine."  Dr.  Pavy  also  considers  the 
bright  red  appearance  of  the  tongue,  so  often  noticed 
in  severe  cases  of  diabetes,  is  an  evidence  of  this 
hypersemic  state  ;  the  idea  suggests  itself  from  its 
appearance,  that  the  blood  is  flowing  through  the 
o 


2IO  Clinical  Chemistry.  [Chap.  v. 

organ  without  being  properly  deprived  of  its  arterial 
character.  With  regard  to  the  nature  of  the  nervous 
lesion  in  diabetes  that  produces  this  vaso-motor 
paralysis  nothing  definite  has  been  determined.  Dr. 
Dickinson  has  stated  that  he  has  found  certain  vas- 
cular and  perivascular  changes  in  the  brain  and  medulla 
oblongata  of  persons  dying  from  diabetes.  His  views, 
however,  have  been  challenged  by  pathologists,  who 
have  found  similar  changes  in  brains  of  those  dying 
from  other  diseases  besides  diabetes,  and  that  they 
are  not  by  any  means  a  constant  lesion  in  diabetes. 
However  this  may  be,  I  think  the  explanation  of  the 
persistency  of  diabetes  mellitus,  a  condition  which 
emphatically  distinguishes  it  from  glycosuria,  will  alone 
be  found  to  depend  on  some  definite  lesion  of  the 
nerve  centres,  either  of  the  cerebro-spinal  or  sym- 
pathetic system.  -  Indeed,  it  has  been  suggested  that 
as  the  vaso-motor  nerves  distributed  in  the  sympathetic, 
besides  being  connected  with  the  spinal  cord  and 
medulla  oblongata,  pass  up  to  spots  at  the  surface  of 
the  brain,  these  possible  vaso-motor  centres  should  be 
examined  in  all  cases  of  diabetes  mellitus.  That 
question  must  be  decided  by  the  morbid  anatomist ;  in 
the  meantime,  the  causes  that  induce  glycosuria  are  of 
greater  interest  to  the  pathological  chemist.  In  these 
cases  it  is  more  than  probable  that  the  vaso-motor 
paralysis  is  induced  directly  by  the  circulation  through 
the  portal  vessels  of  toxic  agents.  Thus,  Dr.  Pavy  has 
shown  that  carbonic  oxide,  which  gives  to  venous 
blood  a  bright  scarlet  colour,  and  a  similar  spectrum 
as  oxygen  does  when  introduced  into  the  portal  veins, 
produces  glycosuria  in  as  marked  a  manner  as  arterial 
blood  ;  and  phosphoric  acid,  he  has  shown,  has  the 
same  efiect.  George  Harley  has  similarly  shown  that 
chloroform,  alcohol,  ether,  and  ammonia  produce 
temporary  glycosuria,  so  also  does  curare  poison. 
Although  it  has  not  been  proved,  it  is  far  from  unlikely 


Chrxp.  v.]  L/TlfyEMfA.  2  I  I 

that  uric  acid  may  liave  tlio  same  eHect,  and  thus 
account  for  tlie  frequent  association  of  glycosuria  with 
tlie  gouty  state.  Even  diminution  of  tlie  alkaline 
condition  of  the  blood  may  play  an  im])ortant  part  in 
producing  this  vaso-niotor  paralysis,  since  it  has  been 
shown  (Dr.  Gaskell  ;  Journ.  Fhj/s.,  No.  1,  vol.  iii.  ; 
1880)  tliat  whilst  alkaline  solutions  cause  powerful 
contraction  of  the  heart  and  capillaries,  dilute  acid 
solutions  have  a  contrary  effect ;  in  this  way  one  can 
see  how  disturbance  in  the  circulation  between  the 
intestines  and  the  liver,  by  permitting  the  acid  chyme 
to  pass  too  rapidly  into  the  portal  vessels,  might  lower 
the  alkalescence  of  the  blood  in  the  portal  circidation, 
and  thus  cause  temporary  vaso-motor  pai'alysis.  In 
some  anomalous  forms  of  diabetes,  disease  of  the  pan- 
creas has  been  noticed  ;  the  cutting  off  of  this  powerful 
alkaline  secretion  may  have  effect  of  diminishing  the 
alkalescence  of  the  blood  in  the  portal  vessels.  Glyco- 
suria is  not  unfrequently  met  with  in  those  who  have 
had  much  mental  labour,  trouble,  or  anxiety.  Bernard 
looked  upon  the  appearance  of  sugar  in  these  cases  as 
a  salutary  effort  of  nature  to  repair  the  injuries  of  the 
organism,  but  it  is  far  more  probable  that  it  depends 
on  a  partial  vaso-motor  paralysis,  an  expression  of  the 
general  nervous  exhaustion. 

(2)  Abnormal  disintegration.  —  Lithcemia.  —  For- 
merly it  was  held  that  tissue  changes  depended  on  the 
amount  of  oxygen  taken  in  by  the  lungs,  so  that  in 
increased  respiration  a  more  intense  combustion  took 
place,  and  metabolism  was  increased  with  the  pro- 
duction of  more  carbonic  acid  and  urea,  whilst  when 
respiration  was  impeded  oxydation  was  imperfectly 
performed,  and  as  a  consequence  many  of  the 
intermediate  products,  as  Uric  acid,  oxalic  acid,  etc., 
were  not  burnt  off,  but  were  eliminated  in  an  imper- 
fectly oxydised  condition.  Upon  this  view  the  late 
Dr.  Murchison  founded  his  views  regardintr  lithcemia. 


212  Clinical  Chemistry.  [Chap.  v, 

"  When  oxydation/'  he  says,  "  is  imperfectly  pei'- 
formed  in  the  liver  there  is  a  production  of  insoluble 
lithic  acid  (uric  acid)  and  lithates  (urates)  instead  of 
urea,  which  is  the  soluble  product  resulting  from  the 
last  stage  of  oxydation  of  nitrogenous  matter.  Persons 
who  habitually  enjoy  the  best  of  health  are  liable  to 
deposits  of  lithates  (urates)  in  the  urine  after  a  surfeit 
of  food,  or  even  after  partaking  moderately  of  one  of 
the  fashionable  dinners  of  the  age.  When  more  food 
is  taken  into  the  blood  than  is  necessary  for  the 
nutrition  of  the  tissues,  the  excess  is  thrown  off  by 
the  kidneys,  lungs,  and  skin  in  the  form  of  urea, 
carbonic  acid  and  water,  or  in  the  imperfectly  oxydised 
forms  of  uric  acid  and  oxalic  acid.  Under  these  cir- 
cumstances, an  excess  of  work  is  thrown  upon  the 
liver  and  the  other  glandular  organs,  and  one 
result  is  that  a  quantity  of  albumin,  instead  of  being 
converted  into  urea,  is  discharged  by  the  kidneys  in 
the  less  oxydised  form  of  uric  acid  or  its  salts.  But 
what  in  most  persons  is  an  occasional  result  of  an 
extraordinary  cause,  is  in  some  almost  a  daily  occur- 
rence, either  from  the  food  being  always  excessive  in 
amount  or  unduly  stimulating,  or  from  some  innate 
defect  of  power,  often  hereditary,  in  the  liver,  in 
virtue  of  which  its  healthy  functions  are  liable  to  be 
deranged  by  the  most  ordinary  articles  of  diet." 

The  doctrine  of  lithsemia,  or,  as  it  ought  more 
properly  to  be  termed,  uricfemia,  has  found  consider- 
able favour  with  the  profession,  no  doubt  from  the 
powerful  advocacy  of  such  a  distinguished  clinical 
teacher  as  Murchison;  but  though  the  numerous 
symptoms  detailed  by  him  in  connection  with  the 
deposit  of  urates  in  urine  are  no  doubt  a  matter  of 
common  observation,  his  explanation  of  the  causes 
giving  rise  to  the  condition  is  not,  I  venture  to  think, 
the  correct  one. 

It  is  now  known  that  uric  acid  is  not  a  necessary 


Chap,  v.]  LiTII/EMlA.  213 

antecedent  of  uroa,  and  tliat  the  latter  hndy  is 
larifoly  formed,  independently  of  the  liver,  directly 
from  the  kreatin  of  muscle  and  from  leucin,  the 
result  of  pancreatic  digestion,  in  the  intestines.  Nor 
liave  we  any  evidence,  except  in  the  state  of  actual 
gout,  that,  in  human  blood,  uric  acid  has  been  ever 
found ;  whilst  the  view  is  steadily  gaining  ground 
that,  with  the  exception  of  a  small  quantity 
formed  in  some  of  the  large  glands  of  the  body,  and 
in  which  it  seems  to  be  destroyed,  uric  acid  is  not 
formed  to  any  extent,  and  that  the  cyanogen  residues 
probably  form  urea  directly  without  passing  through 
the  intermediate  stage  of  uric  acid.  Again,  if  uric  acid 
is  found  in  excess  in  the  urine  because  it  has  not  been 
oxydised  into  urea,  we  should  certainly  expect  to  find 
the  urea  diminished  in  these  cases ;  but  this  is  not 
so.  In  every  analysis  I  have  made  myself,  and  in 
others  that  I  have  referred  to  for  the  purpose  of 
ascertaining  this  point,  I  have  found  that,  whenever 
uric  acid  is  increased,  urea  is  likewise  in  excess,  not 
always  proportionately,  but  still  sufficiently  decided  as 
to  show  there  is  no  reduction  in  quantity. 

The  explanation  I  have  to  suggest  as  a  cause  for 
the  group  of  symptoms  so  admirably  portrayed  by 
Murchison  is,  that  they  are  due  to  a  disturbance  of 
the  nitrogenous  equilibrium,  brought  about  by  an 
increase  of  metabolic  processes  throughout  the  body, 
owing  to  an  intramolecular  activity  in  the  cells  (§  7). 
This  condition  may  be  transient,  and  caused  by  in- 
discretions of  diet,  nervous  influences,  or  temporary 
disturbances  in  some  function  of  the  organism ;  but, 
when  we  have  a  persistent  tendency  to  deposit  urates, 
accompanied  by  increased  urea  and  phosphates,  we 
nmst  look  beyond  mere  defective  oxydation  or  func- 
tional disturbance  of  the  organ  for  an  explanation, 
and  view  it  as  a  prelude  of  some  grave  constitutional 
disturbance    (often  cancer,    tubercle,    or  constitutional 


2  14  Clinical  Chemistry.  [chap.  v. 

syphilis),  the  taiiit  of  which  produces  increased  mole- 
cular activity  throughout  the  body.  This  question  of 
lithseniia  I  have  discvissed  from  its  clinical  aspect  in 
my  work  on  "  Morbid  Urines  associated  with  Derange- 
ments of  Digestion,"  pp.  68 — 76,  and  to  which  I 
refer  the  reader,  as  that  part  of  the  subject  cannot  be 
introduced  here. 

As  a  converse  to  the  conditions  we  have  been 
speaking  of  is  one  characterised  by  a  urine  of  low 
specific  gravity,  with  no  tendency  to  deposit  uric  acid 
or  urates,  and  which  is  very  deficient  in  urea,  and 
associated  with  peculiar  symptoms,  which  Sir  Andrew 
Clarke  has  succinctly  grouped  together  under  the  term 
"  renal  inadequacy."  The  term  is  an  expressive  one, 
and  fixes  in  the  mind  the  condition  of  the  urine  ;  b\it 
I  venture  to  think  in  this  case  we  may  go  a  step 
farther,  and  refer  the  inadequacy  to  failure  in  part  of 
the  metabolic  processes  going  on  throughout  the  body, 
and  in  part  to  defective  assimilation  of  food  by  the 
digestive  organs.  Another  evidence  of  abnormal  dis- 
integration is  occasionally  seen  in  cases  of  temporary 
albuminuria,  and  which  are  sometimes  accompanied 
by  the  presence  of  peptones  in  urine.  This  condition 
is  often  of  a  transient  nature,  and  dependent  on 
marked  disturbance  of  the  hepatic  function.  In  other 
cases,  from  being  at  first  of  a  temporary  and  inter- 
mittent character,  it  becomes  more  and  more  jDer- 
sistent,  as  to  give  rise  to  a  suspicion  that  it  is  a  pre- 
liminary or  early  stage  of  granular  kidney.  Nor  is  it 
at  all  unlikely  that  this  functional  albuminuria  may 
not  at  last  terminate  in  organic  disease.  Ha)matinuria, 
too,  is  another  condition  which  may  be  assumed  to 
depend  on  functional  derangement  of  the  liver.  In  this 
disease  (§  120,  page  161),  only  the  colouring  matter  of 
the  blood  is  present  in  the  urine,  and  no  blood  corpuscles 
are  to  be  found,  whilst  the  colouring  matter  itself  is 
apparently  undergoing  a  change ;  for,  in  addition  to 


Chap,  v.]  Pancreatic  Juice.  215 

the  spt'ctrum  of  oxy-hsemoglobin,  there  is  aLso  a  third 
blind  present,  representing  meth.ienioglobin.  These 
cases  are  usually  attended  with  well-marked  dyspeptic 
symptoms  and  slight  jaimdice,  and  generally  follow 
exposure  to  cold  or  chill.  If,  therefore,  we  regai-d  the 
liver  as  the  seat  of  the  disintegration  of  the  eflete 
blood-corpuscles,  with  the  formation  of  hsematin,  and 
then  of  urobilin,  it  is  not  unreasonable  to  assume  that 
a  sudden  interference  with  the  function  of  the  liver 
may  temporarily  arrest  the  process  of  the  conversion 
of  haemoglobin  into  bile  and  urinary  pigment,  and  so 
permit  it  to  pass  again  into  the  circulation,  to  be 
eliminated  by  the  kidney. 

146.  Pancreatic  juice. — A  thoroughly  reliable 
analysis  of  the  secretion  of  pancreas  is  wanting, 
owing  to  the  fact  that  the  slightest  irritation  of  the 
gland  caus(^s  considerable  changes  in  the  character  of 
the  secretion.  Thus,  Ewald,  at  the  same  period  of 
digestion  in  about  equally  large  dogs,  obtained  some- 
times a  copious,  sometimes  a  scanty,  secretion,  with- 
out being  able  to  assign  any  cause  for  the  difference. 
It  will,  therefore,  be  sufficient  to  state  that  the 
amount  of  solids  in  the  pancreatic  juice  of  dogs, 
obtained  from  permanent  fistulte,  ranges  from  3  to  10 
per  cent.  Of  these,  the  organic  constitute  about 
two-thirds,  and  the  inorganic  one-thii-d.  Of  the  or- 
ganic solids,  the  most  important  are  the  ferments, 
which  act  on  starch,  fat,  and  albumin ;  ordinary 
albumin,  an  albumin  precipitable  by  magnesium  sul- 
phate (casein  or  seroglobulin  %) ;  fatty  matters ;  and 
leucin  and  tyrosin.*  Of  the  inorganic  constituents, 
sodium  carbonate  is  in  relative  excess  of  the  other 
salts.  The  juice,  when  obtained  free  from  the 
products  caused   by  the   irritation   of  the  duct,  is  a 

*  These  bodies  are  not  always  present.  They  seem  to  be 
formed  by  the  action  of  the  proteid  ferment  on  the  albuminous 
constituents  of  the  secretion  after  it  has  been  collected. 


2i6  Clinical  Chemistry.  [Chap.  v. 

clear,  somewliat  viscid  fluid,  free  from  smell,  having  a 
marked  alkaline  reaction. 

The  ferments  of  the  pancreatic  juice  can  be 
obtained  from  the  glycerin  extract  of  the  pancreas 
of  a  freshly-killed  animal. 

(1)  Action  on  starch  is  most  energetic,  and  sur- 
passes that  of  the  saliva  (§  131).  The  ferment  has 
been  isolated  in  a  state  of  tolerable  purity.  It  is 
stated  that,  after  the  pancreas  has  been  exhausted  by 
glycerin,  if  left  exposed  to  the  air  for  some  time,  it 
will  again  yield  the  diastatic  ferment.  From  this,  it 
is  argued  that  the  pancreas  contains  a  body  which  by 
decomposition  is  converted  into  a  ferment,  analogous 
to  the  process  that  occurs  in  the  liver  by  the  con- 
version of  glycogen  into  glucose  (Liversidge ;  Jour. 
Anat.  and  Phys.,  vol.  viii.,  1872). 

(2)  Action  on  fats. — The  ferment  that  acts  on  fat 
has  not  yet  been  isolated.  Its  action,  however,  can 
be  studied  with  the  fresh  juice,  by  mixing  it  with  a 
little  of  a  neutral  fat  in  a  test-tube,  and  placing  the 
mixture  in  a  water-bath  (40°  0.).  At  the  commence- 
ment of  the  process  the  mixture  is  slightly  alkaline, 
and  neutral  to  litmus ;  but,  as  digestion  proceeds,  it 
becomes  acid  from  the  splitting  up  of  the  fat  into 
glycerin  and  fatty  acid. 

(3)  Action  on  jji-oteids. — In  dilute  alkaline  solu- 
tions, the  ferment  converts  proteid  bodies  into  pep- 
tones, similar  to  those  formed  by  pepsin  in  acid 
solutions,  dilute  solution  of  sodium  carbonate,  O'l 
per  cent.,  playing  the  same  part  as  dilute  hydro- 
chloric acid  does  in  gastric  digestion.  The  points, 
however,  in  which  pancreatic  digestion  differs  from 
gastric  digestion  are,  that  the  proteid  elements  do  not 
swell  up,  become  translucent,  and  fibrillate,  as  in  the 
case  of  digestion  with  pepsin,  but  remain  opaque,  and 
apparently  undergo  conversion  from  the  edges  by  a 
process    of    erosion.     Again,    the   bye-product,    anti- 


ciiap.  v.]  Pancreatic  Juice.  217 

albumose  (or  parapeptone)  is  of  an  alkaline  character, 
resembling  alkali,  albumin,  or  casein,  and  not  acid 
albumin  or  syntonin,  as  in  gastric  digestion.  Lastly, 
the  continued  action  of  pancreatic  ferment  leads  to 
the  formation  of  leucin  and  tyrosin  from  the  breaking 
up  of  the  hemipeptone.  The  following  table  shows 
in  a  graphic  form  the  changes  efiected  on  proteid 
substances  respectively  by  gastric  and  pancreatic 
digestion  : 

Albumin. 


Anti-albumose  Hemi-albumose 

or  or 

(parapeptone)  (Meissner's  a  peptone) 


I ' 1  I 1 

Anti-peptone     Anti-peptone  Hemipeptone  Hemipeptone 

or  or  ^  f  Leucin  Indol 

(true  peptone)     (true  peptone)"©  2     Tyrosin  Phenol 

Hypoxantbin  Naphthilamine 

Asparaginic  Sul])huretted 

acid  hydrogen 

Glycocoll  Carbonic  acid 


d  c3 


QT,  g     Normal    diges-  Putrefactive 
Pi  l^  tive  products.        products. 

Thus  the  final  action  of  the  pancreatic  ferment  is 
to  break  up  the  hemipeptone  formed  by  its  own 
digestive  action,  and  the  hemipeptone  formed  by 
gastric  digestion,  into  a  series  of  bodies  related  to  the 
group  of  fatty  acids  (leucin  =  amido-caproic  acid)  and 
the  aromatic  series  (tyrosin  =  amido-propionic  acid  in 
"which  one  atom  of  H  is  replaced  by  oxy-phenol).  The 
formation  of  indol,  phenol,  etc.,  is,  however,  regarded 
as  due  to  putrefactive  changes,  and  not  to  normal 
pancreatic  digestion,  since  the  production  of  these 
substances  is  simultaneous  with  the  appearance  of 
organisms  in  the  solutions.  These  organisms  are 
probably  taken  in  with  the  food  and  find  a  habitat  in 
the  intestines  ;  they  do  not  exist  in  the  pancreas.  The 
chemical    reactions    of    the   true   peptone  formed   by 


2i8  Clinical   Chemistry.  [Chap.  v. 

pancreatic  digestion  are  similar  to  that  formed  by  the 
gastric  juice  (§  135;,  page  186).  The  pancreatic  ferment 
dissolves  mucin ;  and,  according  to  ISTencki,  converts 
gelatin  into  a  peptone  and  glycocoll.  It  has,  like 
pepsin,  no  action  on  lardacein,  nuclein,  or  keratin. 

The  pancreas  is  an  organ  about  which  the  patho- 
logical chemist  has  little  to  say  as  yet.  Fatty  dege- 
neration and  atrophy  of  the  gland  has  been  noticed 
by  Bright,  Frerichs,  Catani,  and  numerous  other  ob- 
servers, in  some  cases  of  diabetes.  By  some  it  is  attri- 
buted as  the  result  of  that  disease.  At  page  211  I 
have  suggested  how  possibly  diminution  of  the  pan- 
creatic secretion  may  induce  glycosuria,  by  dimin- 
ishing the  alkaline  reaction  of  the  blood  in  the  portal 
vessels  from  the  absorption  of  the  contents  of  the 
jejunum  not  having  been  neutralised  by  this  secretion. 
In  cases  of  obstruction  of  the  duct  of  the  pancreas  an 
increase  of  fatty  matters  has  been  noticed  in  the 
stools ;  but  there  are  exceptions  to  this  statement. 
The  matter  of  chief  clinical  interest,  which  ought  to 
be  more  fully  worked  out,  is  the  formation  of  urea 
from  the  leucin  derived  from  pancreatic  digestion,  and 
the  formation  of  indol,  and  its  appearance  as  indican 
in  the  urine.  With  regard  to  the  latter,  it  has  been 
shown  that  as  salicylic  acid  puts  a  stop  to  the  forma- 
tion of  indol  in  albuminoid  solutions  of  pancreatic 
juice,  so  the  internal  administration  of  the  same  acid 
reduces  the  amount  of  indican  in  the  urine,  which 
decreases  exactly  in  proportion  as  the  quantity  of 
phenol  increases.  Indican  is  also  met  with  in  the 
urine  after  ligature  of  the  small  intestines,  and  in 
obstructions  and  other  affections  of  the  intestines  in 
disease.  The  indigo  sometimes  deposited  in  a  free 
state  in  urine,  sweat,  and  urinary  calculi,  is  undoub- 
tedly derived  from  the  indol  formed  in  the  intestines 
by  pancreatic  digestion.  The  indol  apparently  is 
converted  into  indican  in  the  alkaline  blood,  which 


Chap,  v.]  Tnte^tinat.  Dicfstion.  219 

is  comcrted  into  iiuli^ijo,  if  prosciit  in  oxcfss, 
wlu'u  it  comes  in  contact  with  highly  acid  sweat  or 
urine. 

147.  Infostiiisil  diH:o«»tion.  —  Very  little  is 
known  regarding  the  composition  of  the  secretion 
furnished  by  the  intestinal  glands.  According  to 
Thirry  the  succus  entericiis  is  a  yellowish  opalescent 
Huid  of  alkaline  reaction,  having  a  specific  gravity  of 
1-011,  and  contains  about  2-5  per  cent,  of  solids. 
It  dissolves  tibrin,  but  it  is  a  question  whether  it  has 
any  action  on  other  proteid  bodies.  Its  diastatic 
action  on  starch  is  doubted.  It  is  said,  howevei-, 
to  convert  cane  sugar  into  grape  sugar  and  in- 
vert sugar,  and  to  set  up  lactic  acid  fermentation. 
Absorption  of  the  digested  products  takes  place 
tlirougliout  the  intestinal  canal,  but  tlie  process 
must  be  considered  with  reference  to  particular 
tracts  : — (1)  The  duodenum  ;  (2)  the  jejunum 
and  upper  part  of  the  ileum ;  (3)  the  lower  part 
of  the  ileum  and  the  large  intestine.  (1)  In  the  duo- 
denum.— In  the  stomach  most  of  the  ditiusible  sugars, 
and  some  of  the  peptones,  pass  directly  into  the 
gastric  veins ;  but  the  remainder,  consisting  of  para- 
peptone,  the  undigested  albumin,  the  starchy  prin- 
ciples which  have  as  yet  escaped  conversion,  and  the 
oleagineous  matters,  pass  through  the  pyloric  orifice 
into  the  duodenum  as  acid  chyme.  On  reaching  the 
biliary  orifice  a  rush  of  bile  takes  place,  which  causes  a 
precijjitation  of  the  parapeptone,  at  the  same  time  the 
pancreatic  secretion  is  poured  forth  in  abundance. 
The  action  of  these  two  alkaline  secretions  has  the 
efl'ect  of  first  neutralisinij  the  acid  and  then  rendering 
the  contents  of  the  intestine  alkaline.  In  the  mean- 
time, the  emulsionising  and  saponification  of  the  fatty 
matter  is  proceeding,  and  the  chyme  passes  into  (2) 
tJie  jejunum  and  upper  jJCiTt  of  the  ileum  as  chyle.  It 
is  liere  that  tlie  final  digestion  of  the  food  is  effected, 


2  20  Clinical  Chemistry.  [Chap.  v. 

the  pancreatic  juice  converting  the  undigested  albu- 
min and  some  of  the  gastric  peptone  into  anti-peptone 
and  hemipeptone,  which  last  is  converted  into  leucin, 
tyrosin,  etc.  The  starch  is  converted  into  grape 
sugar,  so  is,  probably,  part  of  any  cane  sugar  present, 
whilst  a  portion  commences  to  undergo  lactic  fermen- 
tation. The  fats  meanwhile  are  thoroughly  emulsified 
and  saponified.  These  products  are  quickly  absorbed, 
the  peptones,  the  glucose,  and  a  dextrin-like  body,  pass- 
ing chiefly  in  the  direction  of  the  portal  vessels,  whilst 
the  emulsioned  fat  is  taken  up  by  the  lacteals.  (It  is 
a  question  whether  the  saponified  matters  are  taken 
up,  or  whether  saponification  is  only  subsidiary  to 
emulsion.)  In  the  absorption  of  fatty  matter  the 
bile  acids  undoubtedly  play  an  important  part  by 
aiding  their  passage  through  the  absorbents.  As 
the  fluid  contents  pass  onward  they  gradually 
lose  their  nutritious  constituents,  till  at  (3)  the 
lower  part  of  the  ileum  and  large  intestine  they 
become  more  consistent  and  contain  little  besides  the 
insoluble  residue  of  the  food  and  the  putrefactive 
products,  indol,  etc.,  of  pancreatic  digestion.  The 
reaction,  too,  here  again  becomes  acid  from  the  lactic 
acid  fermentation  set  up  in  the  intestine.  Although 
the  process  of  absorption  is  very  inconsiderable, 
still  it  exists  to  a  very  appreciable  extent,  as  is 
decidedly  proved  by  the  beneficial  result  nutritive 
enema  have  for  a  time  on  patients  who  cannot  other- 
wise be  fed. 

148.  The  faeces  consist  of  that  portion  of  the 
food  which  is  not  taken  up  by  the  absorbents,  and  is 
discharged  from  the  body  mixed  with  some  of 
the  products  of  the  biliary  and  intestinal  secretions. 
Their  amount  must  necessarily  depend  on  the  nature 
of  the  food  taken,  and  on  the  energy  of  the  digestive 
powers.  The  quantity  passed  by  a  healthy  adult 
may  be,  however,  stated  r.t  from  7  to  9  ounces  daily. 


Chap.  V.J  F^CES.  2  2 1 

The  colour  ought  to  be  a  rich  brown,  and  the  surface 
of  the  motion  moist  and  slightly  slimy.  The  odour 
varies  considerably  in  different  persons  ;  in  some,  even 
in  the  healthy,  it  is  particularly  strong  and  offensive. 
Thig^  odour  is  chiefly  derived  from  the  putrefactive 
changes  occurring  in  the  intestine,  and  partly  to  a 
secretion  of  the  glands  of  the  large  intestine.  Those 
who  make  it  their  duty  to  inspect  the  stools  of  their 
patients  will  soon  learn  to  recognise  an  odour  sui  generis 
attached  to  many  disorders  ;  thus,  it  is  easy  to  distin- 
guish by  smell  alone  a  dysenteric  from  a  typhoid 
stool,  etc.  The  follo-sving  is  an  approximate  analysis 
of  the  fjeces  of  a  healthy  adult :  Water,  77-3  ;  Solids, 
22-7;  mucin  2-3,  proteids  5*4,  extractives  1-8,  fats 
1-5,  salts  1-8,  resinous,  biliary,  and  colouring  matters 
5 '2,  insoluble  residue  of  food  4 "7. 

(1)  Albumin. — A  small  quantity  of  coagulable 
albumin  is  always  present  in  normal  fteces,  whilst  in 
cases  of  dysentery,  typhus,  and  cholera,  the  quantity 
passed  is  considerably  increased. 

(2)  Extractives. — Besides  the  occasional  presence 
of  leucin,  certain  fatty  acids,  substances  called  ex- 
cretin,  and  stercorin,  are  present.  The  following  is  an 
account  of  these  substances  and  mode  of  separation, 
though  many  are  sceptical  as  regards  their  existence 
in  a  definite  form,  but  consider  them  to  be  modifica- 
tions of  cholesterin.  {a)  Stercorin.  First  described 
bv  Dr.  Flint,  who  assumes  that  under  ordinary 
circumstances  about  0'6  gramme  is  excreted  daily. 
Dr.  Flint  directs  the  f«ces  to  be  evaporated  to 
dryness,  pulverised,  and  exhausted  with  ether. 
The  etherial  solution  is  then  passed  through  animal 
charcoal,  fresh  ether  being  added,  until  the  original 
quantity  of  ether  extract  has  passed  through.  The 
filtered  etherial  solution  is  then  evaporated,  and 
the  residue  treated  with  boiling  alcohol.  The 
alcoholic   solution    is    evaporated,    and    the    residue 


22  2  Clinical  Chemistry.  [Chap.  v, 

treated  with  a  warm,  solution  of  caustic  potash  to 
dissolve  out  all  the  saponifiable  fats.  The  mixture 
is  then  diluted  with  water,  thrown  on  a  filter,  and 
washed  till  the  droppings  are  clear  and  neutral.  The 
filter  is  dried,  and  the  residue  washed  out  with  ether. 
The  etherial  solution  is  then  evaporated,  and  the 
residue  treated  with  boiling  alcohol,  the  residue  of 
this  solution  yielding  stercorin.  Stercorin,  when  thus 
obtained,  appears  as  a  clear,  amber-coloured,  oily 
substance,  in  ,which  thin,  needle-shaped  crystals,  fre- 
quently arranged  in  bundles,  and  having  their  borders 
split  longitudinally,  appear  in  the  course  of  a  few 
days,  Stercorin  is  neutral,  soluble  in  ether  and  hot 
alcohol,  insoluble  in  water  and  solutions  of  potash  ;  it 
is  distinguished  from  cholesterin  by  having  a  lower 
melting  point,  viz,  38°  0,  Treated  with  strong 
sulphuric  acid  it  gives  a  red  colour,  Dr,  Flint  con- 
siders that  stercorin  is  formed  by  a  modification 
of  cholesterin  in  its  passage  along  the  intestinal 
canal ;  since  a  comparison  of  the  total  quantity  of 
cholesterin  contained  in  bile  with  the  quantity  of 
stercorin  actually  discharged  shows  a  correspondence. 
(&)  Excretin.  This  principle  was  obtained  by  Dr, 
Marcet,  together  with  excretolic  acid,  from  faecal 
matter.  The  faeces  are  first  dried  and  exhausted  with 
boiling  alcohol,  and  the  alcoholic  solution  concentrated, 
filtered,  and  allowed  to  stand ;  after  some  time  a 
granular,  olive-coloured,  fatty  acid,  excretolic  acid,  is 
deposited.  This  substance  melts  at  25°,  is  insoluble 
in  water  and  in  solutions  of  potash,  and  in  cold 
alcohol ;  its  composition  has  not  yet  been  determined. 
The  excretolic  acid  must  be  removed  by  filtration,  and 
the  filtrate  treated  with  milk  of  lime,  which  throws 
down  a  brown  precipitate  ;  this  is  dried  and  exhausted 
with  ether,  which  yields  crystals  of  excretin.  The 
crystals  form  delicate,  silky,  four-sided  prisms,  in- 
soluble in  water  and  solutions  of  potash,  very  soluble 


Chap,  v.]  FMCES.  223 

in   ctlior ;    tlicy   melt   at  95",  and    liave  an  alkaliuo 
reaction. 

3.  Tlio  fats  contain  saponifiable  fats,  and  a  vory 
considerable  proportion  of  cholesterin. 

4.  The  inoryanic  constituents  contain  a  very 
considerable  amount  of  magnesium  and  calcium 
phosphate,  the  former  chiefly  in  the  form  of  ti-iple 
phosphate.  The  fa>ces  are  the  only  instance  in  the 
animal  tissues  and  fluids  in  which  the  magnesium 
salts  are  relatively  in  excess  of  the  calcium  salts  ;  this 
is  owing  to  more  lime  than  magnesia  being  absorbed 
in  the  intestines.  The  potassium  salts  are  also 
relatively  in  excess  of  the  sodium  salts.  The  biliary 
acids  appear  in  the  faeces  in  an  altered  condition, 
as  dyslysin,  cholalic,  and  cholodinic  acids.  The  in- 
soluble residue  consists  of  undigested  muscular  fibre, 
the  outer  envelope  of  vegetable  cells  and  fibres, 
partially  dissolved  starch,  cells  of  cartiLige,  and 
fibres  of  elastic  tissue,  etc.  Faeces  sometimes  con- 
tain a  ferment  like  pepsin,  and  one  that  has  a  dia- 
static  action  on  starch ;  both  are  probably  derived 
from  the  digestive  secretions.  Meconium,  or  the 
faecal  matter  at  birth,  consists  almost  entirely  of 
biliary  matter  and  mucus.  Thus,  a  sample  of  dry 
meconium  yielded  ;  Biliary  matter,  15*6  ;  cholesterin, 
15*4 ;  mucus  epithelium  and  salts,  69  parts  in  100. 

"We  have  very  few  reliable  analyses  of  faeces  in 
disease,  few  having  courage  to  piirsue  diligently  such 
an  unpleasant  business.  As  a  rule  we  learn  much  by 
regular  inspection ;  and  if  the  i)lan  adopted  at  the 
London  Hospital,  of  placing  them  in  large  deep  conical 
vessels,  and  covering  the  mouth  of  the  vessel  with  a 
thick  glass  plate,  inspection  can  be  made  without 
unpleasantness  being  occasioned,  especially  if  with 
loose  stools  a  little  ether  is  floated  over  them. 
In  liquid  stools  the  more  solid  contents  gravitate 
first,   and    so   on,  so  that  a  rough    analysis  can  be 


2  24  Clinical  Chemistry.  [Chap.  v. 

made.  If  a  more  intimate  acquaintance  with  the 
composition  of  the  ffeces  is  desired,  they  must  be 
submitted  to  regular  analysis ;  viz.  :  (1)  By  ascer- 
taining the  amount  of  water  and  solids  (§  92) ; 
(2)  by  agitating  in  water  for  some  time  a  definite 
weight  of  feeces,  filtering  the  aqueous  solution,  and 
coagulating  the  dissolved  albumin,  and  weighing 
n  as  directed  (§  118,  page  145);  (3)  extracting  with 
ether  to  remove  fatty  matters  and  cholesterin  (§  99) ; 
(4)  after  the  removal  of  the  cholesterin,  extracting 
successively  with  boiling  alcohol  and  chloroform  to 
remove  biliary  matters  (page  198);  (5)  whilst  the  salts 
are  estimated  after  incineration,  as  directed  (§  101). 

149.  Intestinal  concretions  will  be  con- 
sidered in  chapter  vi.,  in  the  section  referring  to 
morbid  concretions  and  calculi. 

1.50.  Oases  in  stomacb  and  intestines. — 
As  has  been  well  observed,  though  yeast  fungi  are 
continually  being  taken  with  the  food,  as  in  bad  beer 
or  bread,  and  are  thus  brought  in  contact  with  the 
saccharine  and  albuminous  matters  of  the  food,  which 
are  capable  of  fermenting  in  the  stomach,  fermenta- 
tion does  not  occur  unless  another  condition  is  added. 
The  ferment  must  have  time  and  opportunity  for 
developing  itself.  Under  ordinary  circuuistances  it  is 
so  rapidly  removed  from  the  stomach,  together  with 
fei-mentable  material,  that  the  process  has  no  time  to 
commence.  The  conditions,  therefore,  that  favour  the 
development  of  fermentation  are  those  which  retard 
digestion  either  by  mechanically  obstructing  the 
onward  passage  of  the  food,  or  from  an  abnormal 
condition  of  the  digestive  secretions,  or  the  indigestible 
nature  of  the  food  itself.  From  experiments,  we  learn 
that  under  normal  circumstances  the  gases  found  in 
the  stomach  consist  of  oxygen,  nitrogen,  and  carbonic 
acid,  but  no  hydrogen,  which  we  would  expect  to  find 
if  the  gases  of  the  stomach  in  health  were  formed  by 


Chap.  V.J 


Fla  tus. 


225 


lactic  acid  fcrmontation.  It  is  probaMc,  tliercfore, 
that  of  tho  gasos  olitainod  from  the  stomach  under 
normal  conditions,  the  first  two  arc  derived  from  the 
air  swallowed  with  the  food,  whilst  the  latter  is 
derived  by  difTusioii  from  the  blood.  In  the  small 
intestine,  however,  acetic  and  lactic  acid  fermentation 
commences,  as  is  shown  by  the  preponderance  of 
carbonic  acid  gas,  and  the  presence  of  hydrogen.  The 
following  table  gives  the  result  of  Planer's  analysis  of 
the  gases  of  the  stomach  and  intestine  respectively : 


Stomach. 

Small  intestine. 

Gas. 

Moat. 

Bread. 

Meat. 

Vegetable  diet. 

CO2 
N 
0 
H 

2o-20 

68-68 

6-12 

Nil 

32-91 

66-30 

-79 

NH 

40-1 
45-5 
Trace 
13-86 

47-34 
3-97 

48-69 

The  steps  that  occur  in  this  pi'ocess  of  fermentation 
are  shown  in  the  following  table,  thus  : 

Sugar  C^U^.X), 


2  (CHgO)  Alcohol  +  2  COo 
CaH'gO  +  0  =  CoH^O  Aide- 

hi/de  +  JI.,0 
C2H4O  +  0  =  C^U^OoAcetic 

acid. 


2  (CjHgOg)  Lactic  acid 

CjH'gO.,  +  2  CO2  +  H  Biitt/ric 
acid,  carbonic  acid,  and  hydro- 
gen. 


The  occurrence  of  this  lactic  and  butyric  acid 
fermentation  in  the  small  intestine  in  health,  suggests 
a  way  in  which  the  carbohydrate  constituents  of  food 
may  become  converted  into  fat ;  for,  by  this  lactic 
and  butyric  acid  fermentation,  the  sugar  is  converted 
into  members  of  the  fatty  acid  series.  The  extent, 
however,  to  which  this  fermentation  is  carried  on  in 


226  Clinical  Chemistry.  [Chap.  v. 

health  is  probably  small,  since  if  it  occurred  largely  in 
the  intestine  we  should  have  a  considerable  quantity  of 
free  hydrogen  excreted  by  the  lungs  or  bowels,  which  is 
not  the  case.  The  fermentative  changes  reach  their 
highest  point  in  the  large  intestine,  so  much  so  as  to 
render  its  contents  acid,  in  spite  of  the  alkaline 
character  of  the  secretion  from  its  walls.  Here,  in 
addition  to  hydrogen,  we  have  a  considerable  quantity 
of  marsh  gas  (CH4)  developed  with  sulphuretted 
hydrogen  (HjS),  from  the  decomposition  of  the 
albuminous  and  other  sulphur-yielding  elements  of 
the  food. 

In  disease,  however,  excessive  fermentative  changes 
of  the  food  may  occur,  leading  to  the  production  of 
enormous  quantities  of  gas  and  the  formation  of 
various  intermediate  products,  as  we  have  seen,  such 
as  alcohol,  aldehyde,  and  acetic  acid  on  the  one  hand, 
and  of  lactic  and  butyric  acid  on  the  other.  Some- 
times it  is  a  large  quantity  of  gas  that  is  formed,  at 
another  time  an  excess  of  acid.  Thus,  Ewald  speaks 
of  a  patient  who  pithily  observed  that  "  there  was 
sometimes  a  vinegar  factory  and  sometimes  a  gas- 
works in  his  inside  ; "  in  fact,  at  one  time  alcoholic 
fermentation  led  to  the  formation  of  acetic  acid,  at 
another,  the  butyric  acid  fermentation  produced 
hydrogen  and  carbonic  acid.  It  is  often  difficult  to 
distinguish  clinically  between  the  different  forms  of 
flatulent  distension  which  arise ;  but  we  receive  con- 
siderable aid  if  we  are  careful  to  discriminate  between 
those  forms  where  flatulence  is  the  only  symptom  and 
those  where  it  is  associated  with  acidity,  and  also  by 
taking  into  consideration  the  period  with  regard  to 
digestion  at  which  these  symptoms  develop.  Thus, 
there  are  some  persons,  chiefly  females,  who,  im- 
mediately on  taking  food,  complain  of  flatulent 
distension  without  acidity ;  the  wind  they  bring 
up  is  inodorous.     In  these  cases,  the  gas  does  not 


Chap.  V.J  FlA  TUS.  227 

apparently  result  from  fermentative  changes,  but  is 
probably  derived  by  diffusion  from  the  blood  under 
nervous  influences.  When  the  flatulency  is  accom- 
panied by  a  slight  degree  of  acidity,  and  sets  in  about 
an  hour  after  food,  and  the  risings  are  simply  acid, 
and  the  eructations  comparatively  inodorous,  acetic 
and  carbonic  acid  fermentation  of  the  amylaceous 
and  saccharine  materials  of  the  food  is  indicated. 
When  the  risings  ai'e  distinctly  rancid,  it  is  evidence 
that  lactic  acid  fermentation  of  the  nitrogenous  prin- 
ciples is  progressing.  This  forua  of  fermentation  is 
usually  the  most  obstinate  and  severe,  since  it  may 
continue  independently  of  food  by  the  decomposition 
of  the  mucus  in  the  stomach  and  the  intestinal  canal, 
so  that  flatulence  may  persist  even  when  the  stomach 
is  kept  empty. 

Flatulent  distension  of  the  stomach  and  intestines 
often  arises  in  nervous  states  of  the  system,  appa- 
rently, however,  quite  independently  of  any  fermen- 
tative changes  occurring  in  the  alimentary  canal. 
Indeed,  it  is  quite  impossible  to  account  for  the 
enormous  quantity  of  gas,  which  consists  largely  of 
carbonic  acid,  often  discharged  through  the  mouth  on 
a  perfectly  empty  stomach  by  hysterical  and  hypo- 
chondriacal patients,  except  on  the  supposition  that  it 
is  diffused  from  the  blood. 

The  disturbances  caused  by  fermentative '  changes 
in  the  stomach  are  not  limited  to  that  organ.  The 
acid  products  formed  in.  it,  together  with  the  un- 
digested residue  of  the  food,  pass  on  into  the  in- 
testines, and  excite  more  or  less  pain  and  diarrhoea. 
Again,  fermentative  changes  may  occur  chiefly  in  the 
intestines,  and  only  a  slight  degree  in  the  stomach. 
In  this  case,  which  is  associated  with  a  greater  or  less 
degree  of  chronic  intestinal  catarrh,  a  constipated 
condition  of  the  bowels  generally  exists ;  for,  though 
there   may    be    frequent   loose,   slimy,   and    offensive 


228  Clinical  Chemistry.  [Chap.  v. 

discharges  from  the  bowels,  yet  a  purge  never  fails  to 
bring  away  accumulated  masses  of  fsecal  matter.  The 
whole  of  the  intestinal  tract  may  be  aflfected,  or  only 
part  of  it.  Some  writers  have  asserted  that  the  evil 
effects  of  fermentative  changes  are  more  felt  in  the 
small  intestines  than  in  the  large,  and  that  catarrh  of 
the  .small  intestines  is  generally  associated  with 
oxaluria.  The  flatulence  may  distend  the  whole 
intestinal  tract,  but  one  part  of  it  is  generally  dis- 
tended more  than  another;  and  circumscribed  swell- 
ings occur,  chiefly  in  the  right  and  left  hypochondriac 
regions,  causing  pain  over  the  region  of  the  liver  and 
stomach,  spleen,  or  kidneys,  and  leading  the  patient 
to  suspect  disease  of  these  organs.  But  the  mischief 
resulting  from  excessive  formation  of  acid  in  the 
stomach  and  bowels  is  not  limited  to  mere  disturbance 
of  digestion,  injurious  effects  making  themselves 
manifest  on  the  system  and  on  the  general  nutrition 
of  the  body  when  the  morbid  condition  has  been 
present  for  some  time. 

Thus,  Beneke*  has  pointed  out  that  the  increased 
production  of  lactic  and  butyric  acids  in  the  alimen- 
tary canal  is  frequently  associated  with  oxaluria  {§  112, 
page  130),  since,  as  he  thinks,  the  excessive  formation 
of  these  acids  prevents  the  development  of  the  red 
corpuscles,  so  that  oxydation  is  insufficiently  performed. 
A  catarrhal  condition  of  the  mucous  membrane  of 
the  intestines  he  also  pointed  out  as  being  freqiiently 
found  accompanying  this  condition  ;  he  does  not,  how- 
ever, consider  it  as  being  a  proximate,  but  only  a 
determining,  cause  of  the  disorder.  Whilst  endorsing 
Beneke's  statement  that  deposits  of  oxalate  of  lime 
are  met  with  in  persons  suffering  from  dyspepsia,  at- 
tended with  excessive  formation  of  lactic  and  butyric 

*  "Zur  Phys.  und  Path,  des  Phosphors  und  Oxalsaure 
Kalkes."  1850.  "Zur  Entwicklungsgeschichte  der  Oxalurie." 
185« 


Chap. V.)  Bilious  Attacks.  229 

acids,  T  do  not  consider  his  explanation  to  be  the 
correct  one,  since,  in  these  cases,  1  believe  a  catarrhal 
condition  of  the  mucous  membrane  of  the  digestive 
canal  to  be  the  proximate  cause,  which,  by  hindering 
the  onward  passage  of  the  food,  favours  fermentative 
changes  and  the  production  of  lactic  and  butyric 
acids. 

Again,  the  highly  acid  fluid  containing  the 
imperfectly  digested  products  of  gastric  digestion 
passing  into  the  duodenum  excites  more  or  less 
catarrh  of  that  portion  of  the  intestine,  and  the 
discharge  of  bile  is  interfered  with ;  hence  persons 
suffering  with  flatulent  dyspepsia  have  usually  sallow 
complexions,  complain  of  pain  in  the  hepatic  region, 
and  suffer  frequently  from  so-called  "  bilious  attacks." 
The  absorption  of  the  vitiated  products  of  digestion, 
together  with  some  of  the  free  acid,  produce  many 
general  and  remote  disorders  of  nutrition,  so  that 
a  condition  of  debility  and  exhaustion  is  speedily 
induced. 

151.  Detection  of  arsenic,  antimony,  etc., 
in  the  viscera.  —  A  plan  of  procedure  for  the 
examination  of  vomited  matters  by  which  the 
student  or  practitioner  can  ascertain  the  nature 
of  the  poison,  without  the  expenditure  of  much 
time  or  the  employment  of  elal:)orate  apparatus, 
has  been  detailed  §  136,  page  191.  Of  course,  it  is 
understood  that  these  investigations  are  only  pre- 
liminary to  a  more  searching  investigation  in  the 
chemical  laboratory  at  the  hands  of  an  expert.  In  ad- 
dition to  the  examination  of  the  vomited  matter  ejected 
during  life,  we  should  also  make  an  examination  of  the 
tissues,  es])ecially  of  the  viscera,  after  death,  especially 
if,  as  is  sometimes  the  case,  the  vomited  matters  have 
been  thrown  away  without  having  been  examined,  and 
the  patient  having  lived  some  hours  after  the  poison  h;is 
been  absorbed  from  the  stomach  into  the  tissues.     For 


230  Clinical  Chemistry.  [Chap.  v. 

this  purpose  portions  of  the  liver  and  stomach  must  be 
divided  as  finely  as  possible  and  placed  in  a  porcelain 
dish,  and  a  mixture,  about  twice  the  quantity  of  the 
organic  matter  employed,  consisting  of  six  parts  of  dis- 
tilled water  to  one  of  hydrochloric  acid,  is  added,  and 
the  whole  warmed  for  about  an  hour.  After  this,  small 
fragments  of  potassium  chlorate  are  to  be  dropped  into 
the  mixture  from  time  to  time,  and  the  mixture 
kept  constantly  stirred,  till  the  solid  matter  has 
almost  completely  disappeared.  The  mixture  is  then 
filtered  through  fine  linen,  the  insoluble  matter  left 
oh  it  being  kept  for  further  examination,  and  the  acid 
filtrate  divided  into  three  parts :  (1)  Place  in  the 
acid  mixture  a  strip  of  perfectly  pure  copper  and  boil 
for  twenty  minutes  ;  if  there  is  a  deposit  on  the  copper 
examine  for  arsenic,  antimony,  or  mercury.  Remove 
the  strip  of  copper,  wash  it  with  a  little  distilled  water 
to  which  a  few  di'ops  of  ammonia  are  added,  dry  it 
between  folds  of  blotting  paper,  then  when  quite  dry 
place  it  at  the  bottom  of  a  narrow  glass  tube  ( German 
glass),  and  apply  heat  to  the  lower  portion  of  the  tube, 
taking  care  that  the  upper  end  remains  cool,  and 
placing  the  finger  lightly  over  the  mouth  of  the  tube, 
so  as  to  keep  the  volatilised  matters  within  it.  If 
arsenic,  forms  the  crust  on  the  copper,  then  arsenious 
acid  will  sublime  and  be  deposited  at  the  upper  end  of 
the  tube,  and  this  deposit  under  a  low  power  of  the 
microscope  will  be  found  to  consist  of  sparkling  octo- 
hedi-al  crystals.  Break  ofi"  the  portion  containing  the 
deposit  and  boil  it  in  a  test-tube  for  some  minutes 
with  distilled  water.  Test  aqueous  solution  with  (a)  few 
drops  of  silver  ammonium  nitrate,  which  gives  a  bright 
yellow  precipitate,  soluble  in  ammonia  and  nitric  acid ; 
(6)  solution  of  cupric  ammonio-sulphate,  which  gives  a 
pale  apple-green  precipitate.  If  arsenic  has  been  found 
it  will  be  as  well  to  take  a  fresh  portion  of  acidulated 
filtrate  and  submit  it  to  Marsh's  test.     If  the  crust 


Chap.  V.)    SePARA  TION  OF  METALLIC  FoiSONS.  23  I 

deposited  on  the  copper  is  caused  by  antimony,  it  does 
not,  by  heatinij,  yield  a  crystalline,  but  an  amorphous 
deposit,  and  tliis,  on  the  application  of  a  greater 
degree  of  heat  than  was  required  to  volatilise  the 
arsenic.  To  ])rove  the  presence  of  antimony,  break 
off  the  upper  end  of  glass  tulie,  boil  it  with  dis- 
tilled water  very  slightly  acidulated  with  hydrochloric 
acid.  Through  this  acid  solution  pass  a  stream  of 
sulphydric  acid,  when  an  orange-coloured  precipitate 
will  fall.  If  the  deposit  on  the  copper  is  caused  by 
niercuri/,  on  volatilisation  distinct  globules  will  form 
in  the  upper  part  of  the  tube  ;  for  corroboration  apply 
tests  given  §  132,  page  177.  If  no  result  has  been  ob- 
tained by  boiling  the  copper  in  the  acid  filti-ate,  take 
a  fresh  portion  (2)  of  the  acid  solution  and  warm  it 
and  pass  a  stream  of  sul))hydric  acid  through  it.  A 
black  precipitate  indicates  copper  or  lead.  If  copper, 
on  dipping  the  blade  of  a  knife  in  the  acid  solution, 
which  should  be  concentrated,  it  will  be  deposited 
on  the  surface.  Ammonia  added  gives,  with  solution 
of  copper,  a  light  blue  precipitate,  soluble  in  excess 
of  ammonia  with  the  formation  of  deep  blue  solution. 
Potassium  ferrocyanide  gives,  with  solution  of  cupric 
salts,  a  reddish-brown  precipitate.  This  test  is 
employed  to  show  that  all  the  copper  has  been  de- 
posited from  the  standard  Fehling  solution  in  quan- 
titative estimation  of  glucose  (§  119,  page  153).  If  the 
black  precipitate  is  not  caused  by  a  salt  of  copper,  then 
test  solution  for  lead  as  directed  §  129,  page  172. 
If  no  precipitate  is  caused  by  sulphydric  acid  a 
solution  of  ammonium  hydro-sulphate  is  to  be  added  ; 
if  a  zinc  salt  is  present  a  white  or  yellowish-white 
})recipitate  will  be  thrown  down.  (3)  The  acid 
nitrate  is  to  be  concentrated  to  a  small  bulk,  and  is 
then  rendered  alkaline  by  potash  and  shaken  with  five 
times  its  volume  of  ether.  The  etherial  solution  is 
then  removed  and  allowed  to  evaporate  spontaneously 


232  Clinical   Chemistry.  [Chap.  v. 

in  a  small  glass  dish  and  the  solid  residue  examined 
for  strychnine  or  morphia  by  dissolving  it  in  a  little 
dilute  hydrochloric  acid,  rendering  this  solution  alka- 
line by  sodium  carbonate  and  allowing  the  mixture 
to  stand  till  a  crystalline  precipitate  forms.  This 
is  to  be  collected  on  a  small  filter  and  washed  till 
the  washings  are  no  longer  alkaline.  Then  divide  the 
filter  into  two  parts  and  lay  them  on  white  porcelain 
plates  and  test  respectively  for  morphia  (§  70)  and 
strychnia  (§  71).  The  filtrate  and  the  washings  are 
mixed  together  and  evaporated  to  dryness  in  a  water- 
bath,  and  the  dry  residue  warmed  with  alcohol ;  the 
alcoholic  solution  is  then  to  be  evaporated  to  dryness 
and  the  tests  for  morphia  and  strychnia  applied. 

1 5 2 .  E stiinatioii  of  iiitro g'en. — In  some  physio- 
logical and  pathological  enquiries,  we  wish  to  compare 
the  quantity  of  nitrogen  passed  out  of  the  system  with 
the  faeces  and  urine,  with  the  amount  of  nitrogen  taken 
in  with  the  food.  For  these  investigations  the  soda- 
lime  process,  devised  by  Yoit,  is  the  best.  For  this 
purpose  a  sm-all  tubular  retort,  the  bulb  of  which  is 
about  6  centimetres  deep,  and  3  "5  centimetres  broad, 
with  the  neck  bent  at  right  angles  about  10  centi- 
metres from  the  bulb,  and  drawn  out  into  a  fine  tube 
8  centimetres  long,  and  0*3  centimetres  in  diameter, 
has  placed  in  it  some  soda-lime,  recently  heated  to 
redness,  to  the  depth  of  1'5  centimetres.  The  narrow 
tube  of  the  retort  is  then  fitted  to  a  glass  flask  (of 
150  cc.  capacity)  by  means  of  a  perforated  cork.  The 
delivery  tube  of  the  retort  should  pass  down  almost 
to  the  very  bottom  of  the  flask.  By  means  of  a 
second  hole  in  the  cork  a  glass  tube  is  fixed  which  is 
adjusted  so  as  to  be  above  the  level  of  the  fluid.  The 
apparatus  being  arranged,  100  cc.  of  standardised 
dilute  sulphuric  acid  is  poured  by  means  of  the  glass 
tube  into  the  flask,  and  then  5  cc.  of  urine  (or  in  the 
case  of  faeces   or   food   5  grms.,  weighed    dry,    and 


Chap,  v.]  Estimation  of  Nitrogen.  233 

afterwards  mixed  in  5  cc.  of  wati-r)  ai-e  poured  on  tlio 
soda-liuio.  The  mixture  at  once  becomes  warm  and 
ammonia  is  disenfj;aged,  which  passes  over  into  the 
flask  where  it  bul)l)les  up  through  the  dilute  sul])huric 
acid.  At  this  point  of  the  proce(!ding  there  is  a 
tendency  for  the  sulj)huric  acid  to  be  sucked  up  the 
tube  into  the  retort.  To  prevent  this  the  retort  is 
held  over  a  spirit  lamp  and  heat  very  cautiously 
ajiplied,  care  being  taken  that  while  the  heat  is 
suliicient  to  prevent  the  sulphuric  acid  rising  in  the 
tube  it  does  not  cause  too  violent  disengagement  of 
gas.  When  the  whole  of  the  water  has  passed  over 
from  the  retort  into  the  flask,  and  the  gas  is  passing 
off  regularly  and  steadily,  the  temperature  must  be 
raised.  This  is  done  by  placing  wire  gauze  round 
the  bottom  of  the  retort  and  applying  strong  heat, 
till  the  mixture  in  the  retort  becomes  nearly  white. 
When  this  is  so,  bubbles  of  gas  are  no  longer  dis- 
engaged, and  the  sulphuric  acid  begins  to  rise  in 
the  tube.  The  heat  must  now  be  withdrawn  and 
the  glass  stopper  taken  out  of  the  retort.  The 
flask  is  detached  and  the  contents  poured  into  a 
beaker,  a  few  drops  of  litmus  solution  (page  70)  added, 
and  the  non-saturated  sulphuric  acid  measured  with  an 
equivalent  quantity  of  a  standard  soda  solution.  Thus, 
of  100  cc.  of  the  sulphuric  acid  solution  20  cc.  are  found 
to  be  saturated,  as  ammonia  sulphate,  and  as  1  cc.  of 
sulplmi'ic  acid  =  0'00-i25  grm.  of  ammonia,  or 
0'0035  grm.  of  nitrogen;  then  5  cc.  of  urine  contain 
•0035  X  20  =  "0700  grm.  of  nitrogen.  Consequently 
if  1200  cc.  of  urine  have  been  passed  in  the  24  hours 

•0700x1200         .„„  „      .,  .._Q  .     , 
,  =    lo'o   gims.    01    nitrogen    (258   grains). 

And  so  with  faeces,  if  80  grms.  represent  the  amount 
of  dried  foeces  passed  in  the  24  hours,  of  which  5 
grms.  are  distilled  with  soda-lime,  and  the  resulting 
ammonia    saturates    25     cc.     of    the    sulphuric    acid 


234  Clinical  Chemistry.  [Chap.  v. 

solution,  then  "0035  x  25  =  -0875  grm.  of  nitrogen 
for   every   5   grms.    of    dry  faeces,   and    consequently 

=  1"6  grms.  of  nitrogen  (24"6  grains)  passed 

off  by  the  bowels  in  the  twenty-four  hours.  It  was  by 
this  method  that  the  late  Professor  Parkes  showed  the 
close  parallelism  that  existed  between  the  entrance 
and  exit  of  nitrogen.  Thus,  in  one  case,  with  an 
entrance  of  270  grains  of  nitrogen,  254*04  were  passed 
off  by  the  kidneys,  and  27*74  by  the  bowels,  making  a 
total  exit  of  281*78  grains.  In  a  second  case  the 
entrance  amounted  to  302*6  grains,  and  the  exit 
312*8  grains,  of  which  296*2' grains  passed  off  with 
the  urine,  and  16*6  by  the  bowels.  Panke  also  found 
that  with  an  entry  of  296  grains  of  nitrogen,  26*23 
grains  were  passed  by  the  bowels,  and  281  grains  by 
the  kidneys,  making  a  total  of  307*23  grains  of 
nitrogen. 

The  standard  solution  of  sulphuric  acid  required 
for  the  process  is  made  as  follows  : — 12*6  grammes  of 
oil  of  vitriol  are  weighed  and  diluted  up  to  a  litre  of 
distilled  water ;  the  quantitj^  of  sulphuric  acid  in  each 
20  cc.  should  be  determined  by  barium  chloride 
solution,  so  that  each  100  cc.  of  the  dilute  acid  should 
contain  1*0  gramme  of  sulphuric  acid,  and  this 
corresponds  to  0*425  gramme  of  ammonia,  or  0*35 
gramme  of  nitrogen.  Consequently  1  cc.  contains 
0*00425  gramme,  or  '0035  gramme  of  nitrogen. 

The  sodium  hydi-ate  solution  must  be  standardised 
so  that  20  cc.  of  it  should  exactly  neutralise  20  cc,  of 
the  dilute  sulphuric  acid  solution. 


Urinary  Calculi.  235 


CHAPTER  VI. 

MORBID      PRODUCTS. 

152.  Urinary  and  renal  calculi. — With  re- 
gard to  the  origin  and  mode  of  formation  of  uiinary 
calculi,  it  may  be  stated  that  the  nuclei,  except  in  the 
case  of  foreign  bodies  introduced  from  without,  are 
formed  in  the  kidney,  where  they  may  be  retained  to 
form  a  renal  calculus,  or  pass  down  the  ureter  into  the 
bladder,  and  so  become  vesical.  Their  increase  in 
size  depends  on  additions  made  to  the  original  nucleus 
by  the  constituents  of  the  urine,  and  these  additions 
may  be  either  of  the  same  nature  as  the  nucleus  itself, 
or  may  be  formed  of  other  urinary  constituents,  which 
may  become  subsequently  in  excess,  or  may  be  de- 
posited by  alterations  of  the  reaction  of  the  urine.  In 
considering,  then,  the  history  of  any  given  stone,  we 
have  first  to  ascertain  the  nature  of  the  causes  that 
led  to  the  formation  of  the  nucleus,  and  then  trace  the 
growth  of  the  stone  as  exhibited  by  the  chemical  com- 
position of  its  successive  layei-s.  Various  views  have 
been  advanced  to  explain  the  formation  of  calculi. 
The  ancient  authors  held  that  stone  was  formed  in  the 
urinary  organs  by  a  kind  of  slime  baked  by  the  heat 
and  dryness  of  the  parts,  just  as  a  portion  of  soft  clay 
may  by  extei'nal  heat  be  turned  into  brick  or 
tile.*  This  view  maintained  until  Marianus  Sanctusf 
pointed  out  that  calculi  were  of  two  kinds,  the  one  no 
doubt  formed  by  heat,  but  others  by  cold  and  humidity 
as  marble  was  formed.     Paracelsus  was  the  first  who 

*  Hippocrates  (irtpi  a.ipuiv,  vBariov  romav,  cap.  ix.). 

t  De  lapide  renuni  et  vesica,  in  thesauro  chirurgise,  Petri  UflEen- 
bachii.    Folio,  p.  903.     Francof.  IGIO. 


236  Clinical  Chemistry.  [Chap.  vi. 

submitted  calculous  matter  to  chemical  analysis  (1530). 
He  demonstrated  that  it  was  composed  of  organic 
matter  or  nutritive  principle,  an  earthy  principle,  and 
a  volatile  salt ;  and  he  thought  calculous  matter  was  of 
the  nature  of  tartar,  caused  by  the  union  of  the  nutri- 
tive principle  and  the  saline  spirit  which  coagulated  the 
earthy  matter.  This  view,  with  some  modifications, 
was  held  by  Van  Helmont,  and  the  iatro  chemists  who 
followed,  and  it  ultimately  resulted  in  the  doctrine  of  a 
"concreting  acid,"  so  that  when  Scheele  in  1776  dis- 
covered uric  acid,  it  was  regarded  as  being  the  forma- 
tive principle  of  stone,  and  was  in  consequence 
designated  lithic  acid.  This  view  was  proved 
erroneous  by  Wollaston's  discovery  of  calcium  oxalate, 
ammonio-magnesium  phosj)hate,  and  calcium  phosphate, 
as  constituents  of  some  stones.  These  discoveries, 
Irawever,  gave  too  great  a  prominence  to  the  chemical 
origin  of  stone,  and  the  idea  gained  ground  that 
urinary  calculi  were  the  result  of  a  peculiar  diathesis 
wherein  uric  acid,  oxalic  acid,  or  the  phosphates  were 
formed  in  excess  in  the  system,  and  were  eliminated 
in  such  quantities  that  they  were  precipitated  in  the 
urinary  passages.  The  first  correction  of  this  view 
was  made  by  Front  with  regard  to  uric  acid,  and 
Bence  Jones  Avith  respect  to  phosphates,  both  of  whom 
showed  that  these  substances  for  their  precipitation 
need  not  be  in  excess,  but  that  they  were  precipitated 
even  when  present  in  their  normal  quantities  by 
changes  taking  place  in  the  reaction  of  the  urine. 
About  this  time  Hainey  published  his  researches  on 
molecular  coalescence  (§  11,  page  26),  which  drew 
attention  to  the  important  part  played  by  the 
mucus  of  the  urinary  passages  in  furnishing  the  colloid 
medium  in  which  the  precipitated  matters  were 
moulded.  In  fact  it  was  the  slime  of  Hippocrates, 
the  "  gros  humeurs  gluans,  espais  et  visqueux "  of 
Ambrose  Pare  (1564).     In  all  researches,  therefore, 


Chap.  VI.)  Origin  of  Calculi.  237 

into  tlie  origin  of  stone  the.se  tAvo  branches  of  enquiry 
must  be  taken  in  hand  together,  viz.,  the  nature  of 
the  pi'ecipitated  matters  and  the  supply  of  colloid 
material.  With  regard  to  the  former  our  knowledge 
is  now  pretty  definite,  and  the  causes  of  their  depo- 
sition will  be  found  related  §  111,  page  125,  §  113, 
pages  133  and  134.  Thus  we  have  seen  that  uric 
acid  and  urates  are  deposited  from  highly  acid  urine ; 
calcium  phosphate  from  urine,  alkaline  from  the  fixed 
alkalies  ;  ammonio-magnesium  phosphate  (triple  phos- 
phate) from  urine,  alkaline  from  volatile  alkali  derived 
from  the  decomposition  of  urea ;  and  calcium  oxalate 
probably  from  an  acid  fermentation  of  mucus  in  the 
urinary  passages  as  well  as  from  the  calcium  oxalate 
derived  from  the  system.  With  regard  to  the  nature 
of  the  colloid  medium  various  views  have  been  ex- 
pressed. Thus,  Dr.  Owen  Rees  is  in  favour  of  a  gouty 
catarrh.  Among  the  many  evils  arising  from  the 
gouty  diathesis  is  a  tendency  to  this  kind  of  action  on 
the  part  of  mucous  surfaces.  Others  have  suggested 
some  chronic  sub-inflammatory  condition.  Among  the 
Germans  a  specific  catarrh  [stein-bildenden  catarrh) 
has  found  favoui'.  But  if  stone  originated  from 
catarrhal  or  inflammatory  conditions  it  would  be  more 
frequent  than  it  is,  since  catarrhal  conditions  asso- 
ciated with  deposits  of  urinary  constituents  often  siib- 
sist  together  without  stone  resulting ;  for  instance,  in 
nephritis,  where,  with  abundance  of  tube-casts,  blood 
and  epithelium  poured  into  the  urinary  passages,  we  have 
frequently  co-mingled  urates  and  uric  acid,  deposited 
from  the  concentrated  urine,  yet  stone  is  not  recognised 
as  a  clinical  sequence  of  acute  nephritis.  Again, 
calculus  is  not  infrequently  met  with  in  persons  who 
never  have  given  evidence  at  any  period  of  having 
suffered  from  catarrh,  gouty  or  otherwise.  That  the 
mucus  of  the  urinary  passages  furnishes  the  colloid 
medium  by  which  the  stone  grows  is  undoubted  ;  but 


238  Clinical  Chemistry.  [Chap.  vi. 

I  think  in  the  case  of  the  nucleus,  the  colloid  medium 
is  furnished  in  some  other  way  than  the  mucus  of  the 
urinary  passages.  Some  time  since  I  suggested*  that 
instead  of  the  calculous  matter  being  originally 
deposited  in  the  pelvis  of  the  kidney,  the  deposition 
might  primarily  occur  in  the  cells  forming  the  wall  of 
the  renal  tubules  as  the  result  of  some  vital  impair- 
ment, so  that  the  products  normally  eliminated  by 
them  were  retained  and  deposited  instead.  In  support 
of  this  view  I  would  urge  the  fact,  that,  in  the  urine 
of  those  animals  who  secrete  uric  acid  in  a  semi-solid 
state,  it  is  not  diiEcult  to  find  evidence  of  this  sub- 
stance being  contained  in  the  cells  of  the  renal  epi- 
thelium. Besides,  the  late  Professor  Quekett  {Medical 
Times  and  Gazette,  1851)  gives  the  figure  of  a  crystal 
of  calcium  oxalate  enclosed  in  a  human  renal  cell.  It  is 
more  difficult,  however,  to  prove  that  calculi  are  formed 
in  the  tubules,  since  they  must  readily  shell  out  and 
pass  into  the  pelvis  of  the  kidney.  But  Prout,  as  the 
result  of  his  observations,  came  to  the  conclusion  that 
ui-ic  acid  was  secreted  by  the  mammillary  processes  of 
the  kidney,  in  a  semi-fluid  state,  which  afterwards 
becomes  hard,  and  contracts  as  it  hardens.  Sir 
Benjamin  Brodie,t  in  confirmation  of  Prout,  refers  to 
the  fact  that  in  Dr.  William  Hunter's  Museum,  which 
was  formerly  in  Windmill  Street,  but  which  is  now  in 
Glasgow,  there  are  several  preparations  illustrative  of 
this  point  in  pathology ;  to  wit,  the  formation  of 
calculi  at  the  mammillary  processes.  In  some  of  these 
preparations  "  the  mammillary  processes  have  been 
longitudinally  divided,  and  the  tubuli  uriniferi  are 
seen  blocked  up  with  calculous  matter ;  and  in  one  of 
them,  the   development  of  the  calculus  being  further 

*  Lancet,  vol.  ii.,  1883;  and  Quain's  "  Dictionary  of  Medicine," 
article,  Calculus. 

t  "Lectures  on  Diseases  of  tlie  Urinary  Organs,"  4tli  edition, 
p.  239.    Longman  k  Co. 


Chap,  vi.i  Origin  OF  Calculi.  239 

advanced,  it  is  seen  partly  embedded  in  the  apex 
of  tlie  manimillary  process  and  partly  projecting  into 
the  infundibulum." 

Again,  in  the  uric  acid  infarcts  occurring  in  the 
tubules  of  young  infants  we  find  these  to  consist  of  small 
granules,  spheroids,  etc.,  an  evidence  that  the  deposi- 
tion has  taken  place  in  the  presence  of  a  colloid  ;  and 
this  coUoiil,  I  imagine,  is  more  likely  to  be  a  renal  cell, 
than  furniahed  by  a  gouty,  or  specific  catarrh.  Those 
who  admit  the  proljaljle  formation  of  the  nuclei  of 
calculi  in  tlie  mammillary  processes  of  the  kidney 
attribute  their  formation  to  the  more  concentrated 
condition  of  the  urine  in  the  straight  portion  of  the 
tubule  than  in  the  convoluted  part.  The  degree  of 
concentration  is,  however,  very  slight,  whilst  the  in- 
creased diameter  of  the  tubule  in  this  part  of  it':! 
course,  and  there  being  less  obstruction  to  the  onward 
flow  than  in  the  convoluted  part,  would  more  than  com- 
pensate for  any  increase  of  concentration  that  might 
occur.  The  true  explanation  of  the  occurrence  of  this 
deposit  lies,  I  think,  in  the  diffei-ence  of  the  anatomi- 
cal structure  of  this  part  of  the  tubule.  If  we  examine 
a  urinary  tubule,  we  find  it  composed,  from  the  neck 
of  the  capsule  to  the  commencement  of  the  ductus 
papillaries,  of  a  wall  of  basement  membrane  (tunica 
propria)  on  which  the  epithelial  cells  lie ;  from  the 
ductus  papillaries  to  the  apices  of  the  pyramid  the 
tubules  lose  their  basement  membrane,  so  that  the 
wall  is  here  formed  of  the  epithelium  alone,  just  as 
occurs  in  the  ducts  of  the  sweat  glands  where  they 
perforate  the  epidermis.  This  portion  of  the  tubule  is 
also  less  freely  supplied  with  blood  than  the  other 
parts  of  the  medulla.  In  the  medulla  the  blood  is 
conveyed  by  long  vessels,  the  arteriolfe  rectse,  which 
collectively  enter  the  medulla  from  the  side  of  the 
cortex.  These  arterioliie  rectte  proceed  from  branches 
of  the  renal  artery,   which  also  give  otf  the  ai'teria 


240  Clinical  Chemistry.  [Chap.  vi. 

inter-lobularis  to  tlie  cortex.  The  arteriolse  rectse  run 
towards  the  fissure -like  spaces  in  the  marginal  portion 
of  the  medulla  betweeji  the  fasciculi  of  urinary  tubules. 
A  brush  of  parallel  vessels  arises  from  the  trunk  of 
each  arteriolse  rectas,  and  when  the  vessels  of  this 
brush  come  into  contact  with  the  converging  bundles 
of  the  urinary  tubules,  they  break  up  into  capillaries 
that  form  looped  plexuses  round  the  tubules ;  and  as, 
on  account  of  the  progressive  narrowing  of  the  fissure, 
one  artery  after  another  thus  reaches  the  fasciculus  of 
the  tubules,  so  do  they  successively  break  up  into 
capillaries.  The  number  of  the  arteriolse  consequently 
diminish  towards  the  papillae,  until  in  the  latter 
only  one  or  two  remain,  which  break  up  into  capil- 
laries and  are  distributed  over  the  papillae  themselves. 
It  will  thus  be  seen  that  less  blood  circulates  through 
this  part  of  the  kidney  tubule,  and  we  know  by 
analogy  that  textures  possessed  of  feeble  circulation 
are  particularly  prone  to  undergo  degenerative  change 
of  some  sort  or  other.  The  fact  also  that  the  base- 
ment membrane  disappears  at  this  part  of  the  tubule, 
and  that  the  wall  consists  alone  of  epithelium,  may 
also  tend  to  produce  degenerative  changes  in  the  cells 
composing  it. 

A  consideration  of  the  clinical  conditions  under 
which  we  find  calculus  adds  some  support  to  view  I 
have  adduced.  Calculous  disease  is  most  frequent 
during  the  period  of  childhood,  early  youth,  and  old 
age,*  periods  when  the  tissues,  either  from  rapidity  of 
growth  or  general  impairment  of  vitality,  are  most 
likely  to  undergo  atrophic  and  degenerative  changes. 
After  the  age  of  puberty  and  during  the  period  of 
middle  life  calculi  are  comparatively  rarely  met 
with,  although  attacks  of  gravel  are  common.  We 
frequently  find  the  history  of  a  calculus  associated 
with  some  previous  illness,  in  which  the  "vdtal  powers 
*  Statistics  collected  by  Sir  Henry  Thompson. 


ciiap.  vi.i      Disintegration  OF  Calculi.  241 

]i;i\c  lioeii  iiiurh  oxlmiistod.  Blows  ou  tlie  loins, 
violent  strains  of  the  back,  etc.,  often  load  to  thf3 
formation  of  calculous  matter  in  the  kidney ;  un- 
doubtedly in  some  of  those  cases  extravasation  of  blood 
into  the  tubule  may  form  the  nucleus,  but  there  are 
many  cases  where  a  most  careful  examination  of  the 
nucleus  fails  to  prove  a  liajmic  origin.  The  frequent 
association  of  stone  with  gouty  tendencies  may  be 
explained  by  the  existence  of  this  state  of  impaired 
vitality  and  textural  dogenei-ation,  and  the  calculous 
deposit  that  occurs  in  the  renal  tubules  is  caused  in 
a  similar  manner  as  the  deposits  of  sodium  urate,  in 
the  parts  poorly  supplied  with  blood,  as  the  cartilages 
of  the  joints  and  ear  ;  a  deposit  which  is  undoubtedly 
due  to  the  inability  of  these  tissues  to  eliminate  the 
insoluble  urate. 

But  of  greater  importance  than  the  mode  in 
which  calculi  are  formed  is  the  question  of  their 
disintegration,  since  it  is  upon  a  study  of  the  condi- 
tions that  tend  to  produce  this  result  that  we  can 
hope  to  effect  their  removal  from  the  body.  Calculi 
in  the  renal  or  urinary  organs  break  up,  or  disintegrate, 
in  three  ways  :  (1)  By  fracture  from  direct  violence.  Sir 
Benjamin  Brodie  {op.  cit.  2SG,  287)  has  recorded 
instances  of  stones  being  fractured,  apparently  by 
concussion  against  each  other.  To  allow  of  this,  the 
calculous  material  must  have  been  poor  in  organic 
matter  and  consequently  very  brittle  ;  or  there  may 
have  been  a  friable  layer  interposed  between  two 
narder  ones,  as  in  Dr.  Ord's  case  {Path.  S'oc.  Trans., 
vol.  XXX.,  p.  319).  (2)  Spontaneous  fracture.  Dr. 
Ord  has  collected  several  examples  of  calculi  under- 
going fracture,  ajjparently  from  forces  contained 
within  themselves.  In  two  cases  {Path.  Soc.  Trans., 
vol.  xxviii,  p.  171  ;  vol.  xxix.,  p.  162)  it  seemed  to  be 
caused  by  ex[)ansion  of  the  nuclei ;  in  a  third  (vol. 
xxxii.,  p.  304),  the  spores  and  mycelium  of  a  fungus 


242  Clinical   Chemistry.  [Chap.  vi. 

were  found  mixed  with  the  debris,  and  Dr.  Ord  thinks 
this  fungus  growth  was  the  cause  of  the  breaking  up 
of  the  calculus.  Mr.  Pearce  Gould  has  drawn  my 
attention  to  a  calculus  recently  removed  at  the  Middle- 
sex Hospital,  which  contained,  in  its  interior,  purulent 
fluid  ;  one  can  readily  see  how  changes  in  a  fluid 
contained  within  any  of  the  layers  of  a  calculus  might 
lead  to  its  disintegration,  either  fi'om  disruption  owing 
to  decomposition  of  the  fluid,  causing  the  evolution  of 
gas,  and  so,  as  it  were,  blowing  up  the  calculus  ;  or 
else  from  the  drying  up  of  the  fluid  and  the  caving  in 
of  the  walls  surrounding  the  cavity.  (3)  Disintegration 
hy  medical  means.  In  spite  of  Sir  Henry  Thompson's 
statement,  that  he  "  cannot  find  that  any  patient 
certified  to  have  stone  after  sounding  by  a  competent 
surgeon,  after  a  course  of  any  solvent  being  again 
sounded,  or  submitted  to  autopsy,  was  found  free  from 
stone,"  considerable  success  attended  the  adminis- 
tration of  solvent  remedies  by  the  physicians  of 
the  last  century  for  the  relief  of  vesical  calculi. 
Sir  Henry  Thompson  seems  to  have  overlooked  the 
cases  reported,  by  Stephen  Hales,  F.R.S.,  and  David 
Hartley,  F.R.S.,  of  the  four  patients  examined  and 
treated  in  Guy's  and  St.  George's  Hospitals  by 
surgeons  of  those  institutions  under  the  observation  of 
the  president  and  censors  of  the  Royal  College  of 
Physicians  with  a  view  of  determining  the  merit  of 
the  solvent  treatment.*  Certainly  Cheselden,  Nourse, 
and  Sharp  were  competent  surgeons,  and  not  likely,  in 
testing  what  was  considered  a  quack  medicine,  to  have 
omitted  to  state  the  fact  if  they  had  been  able  to 
detect  a  stone  on  the  subsequent  sitting.  As  these  cases 
have  been  overlooked  by  modern  writers  on  calculous 
diseases,  T  quote  them  in  brief  in  order  to  show  the 
success  attained  by  this  mode  of  treatment. 

*  Tracts  B    (No.    4)   250,  in  the  library  Royal  Medical  and 
Chirurgical  Society, 


Chap.  VI.]  SofMTlON  OF    CaLCUI.I.  243 

Case  I.  Mr.  Gardiner  ;Et.  Gl.  Sounded  by  Mr. 
Nourse,  in  presence  of  Mr.  Wall,  apothecary,  Nov.  30, 
1738.  Stone  detected.  Took  solvents  for  eight 
months,  during  wliich  time  he  passed  many  fragments. 
Sounded  again  Sept.  14,  1739,  by  Mr.  Sharp,  in 
the  presence  of  Mr.  Cheselden,  Mr.  Sainthill,  Mr. 
Belcher;  no  stone  detected;  relief  from  all  symptoms. 

Case  2.  Peter  Appleton,  set.  67.  Sounded  by  Mr. 
Sharp,  Guy's  Hospital,  July  6,  1739,  in  presence  of 
Dr.  Pellet,  President;  R.  C.  Phys.  Dr.  Whittaker, 
Censor ;  and  Dr.  Nesbit.  A  stone  found  which  was 
considered  a  large  one.  Took  solvents  for  five  months, 
during  which  time  he  passed  much  grit.  Sounded 
again  Nov.  9,  by  Mr.  Sliarp,  in  the  presence  of  thirteen 
surgeons  and  physicians  ;  no  stone  could  be  detected  ; 
relief  from  all  symptoms. 

Case  3.  Heniy  Norris,  set.  55.  Sounded  at  St. 
Geoi'ge's  Hospital,  Aug.  17,  1739,  by  several  surgeons. 
Stone  detected.  Took  medicines  four  months,  during 
which  he  voided  a  thick  sediment.  Sounded  again  at 
St.  George's,  Dec.  14;  no  stone  could  be  detected; 
relief  from  all  symptoms. 

Case  4.  William  Brightly,  set.  79.  Sounded  at 
Guy's  Hospital,  Sept.  8,  1739,  by  Mr.  Sharp  and  Mr. 
Gardiner.  Stone  detected.  Took  solvents  for  four 
months,  voided  grit  freely.  Sounded  again  at  Guy's 
Hospital  by  Mr.  Sharp  ;  no  stone  could  be  found. 

In  addition  to  these  well-authenticated  cases,  I 
have  collected  some  130  cases  in  which  the  use  of 
solvent  remedies  was  followed  either  by  complete 
relief  or  diminution  of  the  suffering.  The  introduction 
of  lithotrity  as  an  operation  has  rendered  the  use  of 
solvents  unnecessary  as  regards  the  treatment  of 
vesical  calculi  ;  but  the  question  may  be  asked  why,  if 
such  successful  results  were  obtained  last  century  with 
solvents  as  regards  vesical  calculi,  why  do  we  not 
succeed  with   the   same    remedies    in  treating    renn'. 


244  Clinical   Chemistry.  [Chap.  vi. 

calculi  now  %  The  answer  is,  that  the  conditions 
under  which  renal  concretions  can  be  submitted 
to  solution  are  distinct  from  those  which  subsist 
in  the  case  of  vesical  concretions.  "With  the  latter 
we  have  the  urinary  bladder,  capable  of  holding 
four  ounces  of  strongly  alkaline  fluid  completely 
surrounding  the  stone,  and,  moreover,  easily  kept 
alkaline ;  whilst,  to  increase  the  concentration  of 
fluid  in  the  bladder,  the  patient  was  ordered  to  drink 
sparingly,  and  to  restrain,  himself  from  passing  water  as 
long  as  he  could.  With  renal  calculi,  however,  the 
case  is  different.  The  urine  in  contact  with  the 
calculus  at  any  given  time  is  only  a  small  quantity, 
and  as  this  passes  away  directly  to  the  bladder,  it  is  a 
matter  of  extreme  difficulty  to  keep  the  urine  constantly 
alkaline.  Alkaline  remedies  have,  consequently,  to  be 
given  more  frequently,  and  the  aggregate  amount  of 
alkali  required  to  effect  anything  like  a  decided  chemi- 
cal action  is  much  more  than  would  be  the  case  than 
•when  the  whole  of  the  alkaline  urine  was  collected  in 
the  iirinary  bladder.  Moreover,  there  is  the  greatest 
difficulty  in  maintaining  hour  by  hour  the  urine  in 
an  alkaline  state.  A  dose  of  alkali  is  speedily 
eliminated,  and  though  it  renders  the  urine  strongly 
alkaline  for  a  time,  at  the  end  of  two  hours  the  effect 
has  generally  passed  off,  and  the  urine  becomes  acid. 
So  while  the  urine  in  the  bladder  may  remain  alka- 
line from  the  first  portion  of  the  secretion,  the  latter 
portions  as  they  come  from  the  kidney  may  be  acid. 
Moreover,  the  experiments  of  Bence  Jones,  Parkes, 
Beneke,  and  myself,*  have  shown  that  the  alkaline 
bicarbonates,  whilst  they  render  the  urine  alka- 
line for  a  time,  subsequently  tend  to  increase  the 
acidity.  And  it  is  probable  the  vegetable  salines, 
the  citrates  and  tartrates,  act  similarly,  since  they  are 
reduced  to  the  condition  of  bicarbonates  in  the  blood. 
*  Lancet,  Nov.  9th,  1878. 


Chap.  VI.]  Solution  of  Calculi.  245 

At  all  cvonts,  Dr.  Bence  Jonos  found  that  although 
five  drachms  of  tartrate  of  ammonia  wore  taken  in  one 
day  the  urine  was  not  made  alkaline,  whilst  with  a 
fixed  alkali  like  potash  this  large  dose  was  required  to 
keep  the  urine  alkaline  for  a  portion  of  the  day  only. 
Not  only  also  is  there  a  dilliculty  in  getting  patients  to 
take  these  large  doses  with  sufiicient  frequency  and 
regularity,  but  I  doubt  the  projjriety  of  giving  such 
large  doses  of  the  alkalies  for  long  periods  of  time.  I 
have  found  quite  as  much  good  result  from  the  con- 
tinued use  of  distilled  or  soft  water.  Dr.  Murray,  a 
few  years  back,  called  attention  to  this  mode  of  treat- 
ment, and  I  have  since  employed  it  in  all  cases  coming 
under  my  notice,  and  I  can  fully  confirm  all  Dr. 
Murray  said  in  its  favour.  In  one  case  {Path.  Soc. 
Trmis.,  vol.  xxxiii.,  p.  206)  the  calculus  was  passed  as 
a  mere  shell,  much  eroded,  after  two  years'  persistence 
in  the  use  of  soft  water,  just  at  a  time  when  the 
question  of  operative  px'ocedure  was  being  entertained. 
In  cases  of  smaller  calculi  they  came  away  more  freely, 
their  surface  being  eroded,  showing  that  some  diminu- 
tion in  bulk  had  been  occasioned.  The  action  of 
distilled  water  in  promoting  the  disintcgi'ation  of 
calculi  ma}'  be  explained  by  its  taking  up  inorganic 
matter  and  withdrawing  it  from  the  body  ;  whilst  by 
taking  four  pints  daily  of  soft  water  instead  of  four 
pints  of  ordinary  drinking  water,  about  80  grains  of 
saline  constituents  (chiefiy  lime  salts)  are  cut  off.  It 
is  evident,  therefore,  if  we  diminish  the  supply  of 
inorganic  matter,  less  will  be  withdrawn  from  the 
body,  so  that  after  a  time  the  urine  will  contain  less 
and  less ;  and  it  has  been  shown  that  the  poorer 
calculi  are  in  inorganic  constituents,  the  greater  their 
tendency  is  to  disintegrate.  Again,  soft  water  has  a 
powerful  diuretic  action,  increasing  the  urinary  fiow 
by  12  to  20  per  cent,  and  diminishing  the  specific 
gravity.     Now,  Mr.  Rainey  in  his  work  on  molecular 


246  Clinical  Chemistry.  [Chap. vi. 

coalescence  has  shown  that  bodies  placed  in  solutions 
of  diiferent  density,  to  that  in  which  they  were  formed, 
have  a  tendency  to  undergo  molecular  disintegration. 
Lastly,  soft  water  seems  to  diminish  the  catarrh  of 
the  urinary  passages,  and  thus  prevents  the  excessive 
formation  of  mucus,  which  aids  in  the  growth  of  the 
calculus.  This  is  a  point  that  ought  to  be  more 
attended  to  than  it  is,  for  not  only  does  the  reduction 
of  the  catarrh  prevent  any  further  increase  in  growth, 
but  it  gets  the  urinary  passages  into  a  better  state  to 
allow  the  passage  of  the  stone. 

Chemical  examination  of  itrinary  calculi.  — 
Notice  the  size  and  general  appearance,  whether  in 
section  they  are  made  up  of  concentric  layers,  or  pre- 
sent a  uniform  surface.  A  portion  of  the  stone  is 
then  broken  down  and  reduced  to  powder.  If  the 
stone  is  made  up  of  different  layerg,  a  portion  of  the 
powder  of  each  layer  must  be  submitted  to  analysis. 

Class  I.  Little  or  no  residue  is  left  when  a  small 
portion  of  the  powder  is  burnt  on  platinum  foil  under 
the  blow-pipe.  The  calculus  may  consist  of  Uric  acid, 
Xauthin,  Cystin,  or  Hsemic  elements,  or  is  Fibrinous, 
or  composed  of  Urostealith. 

(1)  Uric  acid  calculi  are  the  most  common  of  all 
calculi,  constituting  about  80  per  cent,  of  all  varieties, 
and  often  attain  a  considerable  size ;  they  are  usually 
smooth,  and  of  a  light  yellow  or  reddish  -  brown 
colour.  The  burnt  powder  evolves  an  odour  of 
prussic  acid  and  of  burnt  animal  matter ;  the  ash  is 
extremely  small,  and  contains  traces  of  sodium  phos- 
phate and  carbonate.  Dissolved  in  liquor  potasses, 
and  reprecipitated  by  the  addition  of  hydrochloric  acid, 
the  characteristic  crystals  will  be  observed  under  the 
microscope.  Heated  with  nitric  acid  and  touched  with 
ammonia  the  purple  colour  (murexide)  will  be  produced. 


Chap.  VI.)  Analysis  of  Calcvi.t.  247 

(2)  Xanthiii  cnlcitii  are  cxtrcinely  rare  ;  they  are 
usually  smooth,  and  of  a  oinnaiiion  colour,  taking  a 
polish  when  rubbed.  They  dissolve  in  nitric  acid 
without  eft'ervoscence  ;  and  do  not  yield  the  murexide 
reaction  with  nitric  acid  and  annnonia.  To  obtain 
crystals  of  xanthin  dissolve  a  little  of  the  powder  in 
hydi'ochloric  acid  on  a  glass  slide,  and  allow  the  solu- 
tion to  evaiioratc  slowly. 

(3)  Cystin  calculi  are  also  very  rare,  they  have  a 
smooth  surface,  a  greenish -yellow  colour,  and  break 
with  a  crystalline  fracture  ;  they  are  the  softest  of  all 
calculi,  and  for  some  days  after  their  removal  are  com- 
pressible. Cystin  dissolves  in  the  caustic  alkalis  and 
in  strong  mineral  acids  ;  on  evai)orating  the  ammonia 
solution  cy.stin  is  deposited  in  regular  hexagonal 
tables  ;  on  evaporating  the  hydrochloric  solution  cystin 
crystallises  in  radiating  needles.  Boiled  in  a  solution 
of  caustic  potash  with  a  little  lead  acetate,  a  black  pre- 
cipitate of  lead  sulphide  is  thrown  down,  which  is 
due  to  the  presence  of  sulphur  contained  in  the  cystin. 

(4)  Ha'inic,  fibrinous,  vrosteal'dlt,  Siwd  incliffo  concre- 
tions clear  considerably,  and  leave  little  or  no  ash. 
The  ha'mic  concretions  both  microscopically  and 
chemically  show  that  they  are  derivations  from  blood. 
Tlie  liljrinous  concretions  give  the  reaction  of  tibrin. 
The  urostealith  concretions,  which  are  a  mixture  of 
fatty  and  soapy  matters,  mucus  and  withered  cell 
forms,  dissolve  in  ether.  Concretions  of  indigo  are 
sometimes  met  with.  [See  Dr.  Ord's  case,  Path. 
Soc.  Trans.,  vol.  xxix.,  p.  155.)  The  best  test  for 
the  presence  of  indigo  is  the  reducing^  action  of 
glucose  in  an  alkaline  solution  (§  119,  page  150). 
The  probable  explanation  of  the  deposit  of  indigo 
in  the  urine  will  be  found  §  77,  page  53. 

Class  II.  A  considerable  residue  is  left  when  a 
small  portion  of    the  powder   is    l)urnt  on    platinum 


248    '  Clinical  Chemistry.  [Chap.  vi. 

foil.  The  calculus  may  consist  of  Calcium  phosphate, 
Ammonio-magnesium  phosphate,  Calcium  oxalate.  Cal- 
cium carbonate,  or  Urates. 

(1)  Calcitmi  phosphate. — Calculi  composed  solely  of 
this  substance  are  extremely  rare  ;  when  met  with  they 
are  often  of  considerable  size.  They  have  a  white 
chalky  appearance,  and  their  surface  is  very  friable. 
Most  commonly  calcium  phosphate  is  mixed  with, 
ammonio-magnesium  phosphate,  forming  the  mixed  or 
fusible  calculus  (q.v.).  The  ash  does  not  fuse  (infusible) 
under  the  blow-pipe,  is  soluble  without  effervescence 
in  hydrochloric  acid.  The  acid  solution  gives  a  pre- 
cipitate with  ammonium  oxalate,  indicating  the  pre- 
sence of  lime ;-  and  a  yellow  precipitate  with  uranium, 
nitrate,  shows  the  presence  of  phosphoric  acid. 

(2)  Ar)i7)ionio  -  7)iagnesiuin  phosphate,  rare  as  an 
entire  concretion,  but  frequent  as  a  layer  or  crust  of 
other  calculi.  Since  it  is  formed  whenever  the  urine 
becomes  alkaline  from  the  presence  of  volatile  alkali 
(ammonia),  the  result  of  ureal  decomposition  set  up  by 
morbid  state  of  the  urinary  passages,  and  thus  it  be- 
comes a  frequent  component  of  urinary  calculi.  Under 
tbe  blow-pipe  the  ash  fuses  with  difficulty,  and  dis- 
solves in  hydrochloric  acid  without  effervescence.  The 
acid  solution,  when  ammonia  is  added  in  excess,  throws 
down  the  characteristic  crystals  of  triple  })hosphate. 

(3)  Fusible  calculus,  a  mixture  of  calcium  phos- 
phate and  triple  phosphate,  often  with  some  addition 
of  calcium  oxalate ;  frequently  attain  a  considerable 
size  in  a  short  time.  Under  the  blow-pipe  fuses  into 
a  glistening  enamel,  which  adheres  firmly  to  the  pla- 
tinum foil  on  which,  it  is  fused.  The  powder  of  the 
calculus  dissolves  readily  in  hydrochloric  acid  ;  the  acid 
solution,  on  the  addition  of  ammonium  oxalate,  throws 
down  a  precipitate  of  calcium  oxalate,  indicating  the 
presence  of  lime.  If  this  is  filtered  off  and  ammonia 
added,  crystals  of  triple  phosphate  will  crystallise  out. 


Chap.  VI.]  Analysis  of  Calculi.  249 

If  the  calculus  contains  traces  of  calcium  oxalate,  the 
ash  will  dissolve  with  etlervescence,  and  a  portion  of 
the  calculus  itself  will  not  dissolve  in  acetic  acid. 

(4)  Calcium  oxalate  calculi  are  either  small  and 
pale-coloured,  or  large,  dark-coloured,  with  a  rough, 
irregular  surface,  and  on  section  present  an  angular 
structure,  with  in-egular,  dark-coloured  laminte.  The 
smaller  calculi,  from  their  size  and  a})pearance,  are 
termed  "hemp-seed  calculi;"  the  larger  "mulberry 
calculi."  Very  rarely  it  is  deposited  on  other  calculi  in 
a  crystalline  form.  {See  case  reported  by  Mr.  Morrant 
Baker,  Path.  Soc.  Travis.,  vol.  xxv.,  p.  261.)  Heated 
on  platinum  foil,  it  first  of  all  chars  from  the  com- 
bustion of  the  organic  matter,  and  gives  off  an  odour 
of  burnt  animal  matter ;  finally  the  residue  becomes 
white,  and  consists  of  calcium  carbonate,  which  dis- 
solves with  etlervescence  on  the  addition,  of  hydro- 
chloric acid,  owing  to  the  reduction  of  the  oxalate  to 
a  carbonate  by  combustion.  This  solution,  when 
neutralised  with  ammonia,  throws  down  a  precipitate 
of  calcium  oxalate  on  the  addition  of  oxalic  acid.  X 
portion  of  the  calculus  itself  is  insoluble  in  acetic  acid. 

(5)  Calcium  carbonate  calculi  are  rare,  but  when 
met  with  are  generally  multiple,  occurring  in  large 
numbers,  often  derived  from  the  prostate  gland.  They 
ares})herical  in  shape,  sometimes  cubical  or  pyramidal. 
On  section  they  appear  to  be  composed  of  concentric 
rings,  and  by  polarised  light  they  sometimes  display  a 
dark-looking  cross.  Powdered,  they  dissolve  in  hydro- 
chloric acid  with  effervescence.  Under  the  blow-pipe 
the  powder  slowly  fuses. 

(6)  Urates. — Calculi  composed  entirely  of  urates  are 
veiy  rare;  they  are  generally  found  mixed  with  uric  acid. 
They  are  distinguished  from  this  l)ody  by  the  powder 
being  soluble  in  hot  water,  which  dissolves  the  urates, 
leaving  the  uric  acid.  The  filtrate  evaporated  gives 
with  nitric  acid  and  ammonia  the  murexide  reaction. 


250  Clinical  Chemistry.  [Chap.  vi, 

153.  Biliary  calculi  vary  in  size  from  mere 
grains  to  masses  as  large  as  pigeon's  eggs,  or  even 
larger,  since  stones  measuring  from  two  to  two  and  a 
half  inches  long,  and  one  inch  thick,  are  to  be  found  in 
most  hospital  museums.  Their  number  is  in  inverse 
proportion  to  their  size  ;  the  smaller  they  are  the  more 
numerous.  Some  thousands  of  small  calculi,  varying 
in  size  from  a  grain  of  sand  to  that  of  a  small  pea,  are 
often  recorded  as  having  been  removed  from  the  gall 
bladder.  The  medium-sized  stones  are  generally 
multiple,  but  they  are  not  present  in  such  excessive 
numbers,  whilst  the  large  stones  are  usually  solitary. 
It  is  rare  for  one  stone  to  differ  from  its  fellows,  taken 
from  the  same  gall  bladder.  However  numerous  the  cal- 
culi may  be,  or  variable  in  size,  in  external  appeai'ance 
and  chemical  composition  they  will  be  found  to  cor- 
respond. Gall  stones,  though  more  or  less  rounded 
form,  vary  considerably  in  shape  \  thus  they  may  be 
cubical,  pyramidal,  polyhedral,  etc.,  with  the  edges 
rounded  off  and  facetted,  or  their  plane  surfaces  ren- 
dered concave.  These  changes  from  the  rounded  or 
ovoid  form  are  brought  about  by  mutual  pressure,  when 
there  are  more  than  one  calculi  present  in  the  gall 
bladder.  With  solitary  calculi  the  rounded  or  ovoid 
form  is  generally  preserved.  Foliated  and  branched 
concretions  are  rarities.  In  external  appearance  they 
are  generally  smooth  and  slightly  greasy  to  the  touch. 
Others  have  roughened,  nodulated  surfaces,  resembling 
in  appearance  lychee  nuts.  The  colour  varies  from 
a  dirty  white  to  a  yellow-brown,  or  even  deep  black 
colour.  The  prevailing  shades,  however,  are  brownish 
black  (sepia),  deep  olive-green,  and  russet  brown.  In 
consistence  they  are  soft,  excei)t  in  some  forms,  when 
the  crust  consists  largely  of  lime  salts.  This  portion  of 
the  calculus  is  often  unusually  hai-d.  On  section  biliary 
calculi  present  a  variety  of  appearances.  They  may  have 
a  simple  uniform  structure,  apparently  homogeneous 


Chap,  vi.i  Gall  Stones.  251 

throufchout,  breaking  with  eitlier  a  crystalline  or 
an  earthy  fracture  ;  these  calculi  are,  however,  com- 
paratively rar<\  The  most  common  forms  are  those 
that  present  a  distinct  nucleus,  a  hody,  and  sometimes 
a  crust  or  thin  rind  covering,'  the  body.  The  nucleus,  in 
recent  calculi,  is  generally  homogeneous  in  appearance, 
but  in  old  and  dry  gall-stones  it  is  often  shrivelled  and 
fissured.  It  consists  for  the  most  part  of  inspissated 
mucus,  -with  bile  pigment  and  cholesterin ;  sometimes 
it  consists  almost  entirely  of  cholestcirin.  Foreign 
])odies  often  form  the  nuclei.  Thus,  round  worms, 
distoma,  fragments  of  needles,  plum  stones,  aggre- 
gations of  quicksilver,  have  all  been  met  with  in  the 
interior  of  biliary  calculi.  The  body  of  the  calculus 
on  section  presents  {a)  an  amorphous  appearance  of 
brownish-yellow  colour,  the  material  being  arranged  in 
concentric  layers  round  the  central  nucleus,  the  external 
surface  having  sometimes  a  crust  or  rind,  but  oftener 
no  distinct  crust  or  rind  can  be  made  out.  [h)  From 
the  nucleus  long  stratified  ci'ystals  of  cholesterin 
radiate  towards  the  circumference  of  the  stone,  which 
is  covered  with  a  dense  and  often  nodulated  crust. 
Various  explanations  have  been  offered  to  explain  why 
some  calculi  are  amorphous  and  others  crystalline. 
Sehueppel  thought  that  it  was  the  mingling  of 
the  bile  colouring  matter  with  the  cholesterin  that 
prevented  it  separating  in  the  crystalline  form. 
Wherever,  then,  according  to  this  view,  there  is 
much  pigment,  the  calculi  are  amorphous.  Dr.  Ord 
{Path.  Soc.  Trons.,  vol.  xxxi.,  p.  141)  explains  it 
thus  :  "When  first  precipitated  the  cholesterin  is  dis- 
seminated through  a  bed  of  biliary  pigment,  a  colloid 
of  high  molecule.  This  not  only  prevents  the  forma- 
tion of  separate  crystals,  but  tends  to  group  the 
crystalline  matter  into  spherules.  If  the  colloid  always 
remained  a  colloid,  no  fui-ther  change  would  occur;  but 
the  colloid  pigment  tends  in  process  of  time  to  become 


252  Clinical  Chemistry.  [Chap.  vi. 

crystalline,  and  as  step  by  step  it  assumes  that  con- 
dition, the  two  substances  are  segregated  into  two 
zones,  a  central  one  of  the  more  adhesive  pigment, 
an  outer  one  o£  the  polar  crystal.  An  experiment  of 
Dr.  Ord's,  showing  the  separation  of  cholesterin  from 
bile  pigment,  after  deposition  in  com.bination  there- 
with, may  be  cited  in  illustration  of  the  proposition 
advanced.  A  gall  stone  containing  a  great  deal  of 
pigment  is  reduced  to  fine  powder.  Some  of  this  is 
mixed  on  a  glass  slip  with  glycerin  and  glacial  acetic 
acid,  and  the  mixture  is  covered  with  thin  glass.  The 
slip  is  then  slowly  heated,  over  a  spirit  flame,  to 
ebullition.  When  the  powder  is  in  gTcat  part  dis- 
solved, the  slip  is  transferred  to  the  microscope.  The 
fluid  is  found  in  a  state  of  great  agitation,  and  filled 
with  very  small  yellowish  spherules,  which  run 
together  to  form  large  spherules  of  all  sizes.  These 
move  about  the  field  under  the  influence  of  the 
currents,  with  all  sorts  of  amoeba-like  changes  of  out- 
line ;  but  they  are  perfectly  homogeneous,  and  do  not 
afiiect  polarised  light.  Presently  they  become  station- 
ary, lose  their  transparency,  and  begin  to  crystallise, 
the  process  beginning  at  one  point  and  extending 
thence  quickly  over  the  whole  mass.  The  crystallisa- 
tion converts  them  into  lozenge-like  bodies,  covered 
with  somewhat  round  or  angular  projections,  finely 
marked  with  bent  parallel  lines  indicating  imprisoned 
acicular  crystals.  Very  often  the  interior  remains 
uncrystallised,  but  in  a  state  of  evident  tension  for 
some  time.  The  crystals  are  perfectly  colourless,  the 
pigment  being  separated  from  them  in  subcrystalluie 
nodules  of  a  brilliant  yellowish-red,  like  that  of  hsema- 
toidin.  After  a  varying  time,  sometimes  many  hours, 
the  imprisoned  raphides  burst  from  their  envelope, 
and  the  whole  mass  bristles  with  them,  star-fashion. 
At  the  same  time  the  tense  interior  arranges  itself  in 
concentric   laminae   of    parallel    radiating   crystalline 


Chap.  VI.]  J  X.I  LIS /S   OF    GaLL    StoNES.  253 

fibres,  still  coini)l(!toly  separate  from  the  pignieiit, 
which  forms  alternate  layers  ;  so  that  we  liave  befort; 
our  eyes,  within  a  few  hours,  the  spectacle  of  the 
formation  of  a  tiny  biliary  calculus. 

In  this  experiment,  however,  the  solution  of  cho- 
lesterin  and  bile  pigment  was  first  heated,  and  it  is 
natui-al  to  ex})ect  tliat,  in  cooling,  the  least  soluble  of  the 
two  would  separate  out  first,  and  that  would  be  the 
cholesterin  ;  but  it  is  doubtful  whether  the  conditions 
for  such  separation  exist  in  the  body,  unless  the  choles- 
terin is  in  considerable  excess.  I  believe  the  whole 
question  depends  simply  on  the  amount  of  mucus  pre- 
sent in  solution.  If  this  is  in  excess,  then  the  choles- 
terin separates  out  slowly  in  an  amorphous  form,  carry- 
ing with  it  the  pigment.  If  the  mucus  is  not  abundant, 
and  the  cholesterin  is  in  excess,  it  is  deposited  rapidly 
in  a  semi-crystalline  state,  leaving  the  pigment  behind. 
A  chemical  examination  of  these  calculi  shows  that 
after  the  cholestei'in  has  been  removed  by  ether  there 
is  very  little  organic  residue,  whilst  the  crust  is  poor 
in  pigment  but  rich  in  lime  salts,  which  sometimes 
assiune  a  rod-like  spiculated  form.  All  gall  stones 
contain  cholesterin.  Some,  indeed,  consist  almost 
entirely  of  this  substance,  these  concx-etions,  which 
are  not  frequent,  being  generally  met  with  in  young- 
children.  The  mixed  calculi  are  by  far  the  most 
conjinon,  containing  a  variable  proportion  of  choles- 
terin, from  20  to  90  per  cent.,  mixed  with  bile  pigment, 
traces  of  a  fatty  acid  in  combination  with  lime  (mar- 
garate  of  lime;  Frericlis),  and  sometimes  a  small  quan- 
tity of  bile  acids,  and  an  organic  matrix  derived  from 
the  mucus  of  the  gall  bladder.  The  inorganic  residue 
consists  chiefly  of  lime  salts,  carbonates  and  phosphates, 
traces  of  iron,  and  sometimes  copper. 

An  analysis  of  gall  stones  is  conducted  as  follows  : 
Separate  portions  of  the  crust,  the  body,  and  the 
nucleus,  are  to  be  submitted  for  analysis.     Weigh  a 


254  Clinical  Chemistry.  [Chap.  vi. 

fragment,  incinerate  under  the  blow -pipe,  "weigh 
the  ash ;  the  difference  represents  the  amount  of  or- 
ganic matter  present ;  examine  for  lime  salts  (§  84). 
Thoroughly  exhaust  another  portion  with  ether,  decant 
off  the  etherial  solution  and  evaporate ;  weigh ;  this  gives 
the  amount  of  cholesterin  present.  Test  for  cholesterin : 
by  adding  a  drop  of  nitric  acid,  heating,  and  touching 
residue  with  ammonia,  when  a  reddish-brown  color- 
ation will  be  given ;  or  by  evaporating  with  ferric 
chloride,  and  touching  with  hydrochloric  acid,  when  a 
violet  blue  is  yielded.  The  residue  left  after  exhaus- 
tion with  ether  is  then  treated  with  chloroform,  and 
the  chloroformic  solution  evaporated,  when  a  brownish 
powder  of  bile  pigment  will  be  obtained  (§  140).  Some 
calculi  consist  almost  entirely  of  pigment.  They  are 
rare,  however,  are  small  like  gravel,  and  have  a  tarry 
blackish  lustre.  When  broken  across  they  appear 
homogeneous. 

154.  Pancreatic  calculi  are  of  rare  occurrence, 
usually  associated  with  an  atrophied  condition  of  the 
gland.  They  are  generally  multiple,  and  are  found  in 
the  main  and  accessory  duct  of  the  organ.  They  are 
oval  in  shape,  and  their  surface  often  presents  a  worm- 
eaten  appearance  of  whitish  colour,  which  when 
,  rubbed  acquires  an  enamel-like  lustre.  When  broken 
across,  the  fracture  presents  a  glistening  white  porce- 
lain appearance.  In  some  calculi  I  reported  on  for 
the  Chemical  Committee  of  the  Pathological  Society 
(Trans.,  vol.  xxiv.,  p.  137)  I  found  they  consisted  of 
24  per  cent,  organic  matter,  and  76  per  cent,  inorganic 
ash.  The  latter  chiefly  consisted  of  calcium  carbonate, 
calcium  phosphate  being  in  smaller  proportions ;  the 
soluble  salts,  chlorides  and  carbonates  of  potash  and 
soda,  being  extremely  small.  Process  of  analysis : 
Weigh  a  portion  of  the  calculus,  reduce  it  to  fine 
powder,  incinerate,  weigh  ;  the  difference  in  weight 
gives  the  amount  of  organic  matter  and  water.    Divide 


Chap.  VI .  1  PaNCREA  TIC    Ca  LCULl.  255 

the  ash  into  two  portions.  With  one,  estimate  amount 
of  lime  (§  8-i),  potash,  and  soda  (§  88).  With  the  other, 
dissolve  a  part  in  acetic  acid,  and  estimate  the  phos- 
phates (§  113);  and  tlie  other  part  in  hot  water  to 
determine  the  chlorides  (§  114).  The  carbonates  are 
deteraiined  as  follows  :  A  weighed  portion  of  the  ash 
is  dissolved  in  water  and  introduced  into  a  small  flask  ; 
this  flask  is  fitted  with  a  bulb  tube  fllled  with  dilute 
nitric  acid,  which  is  prevented  from  flowing  into  the 
mixture  by  means  of  a  pinchcock.  The  apparatus  is 
now  weighed  and  attached  to  another  flask  containing 
concentrated  sulphuric  acid,  and  the  bulb  tube  pushed 
down  to  nearly  the  bottom  of  the  flask,  the  pinchcock 
pressed  and  the  dilute  nitric  acid  allowed  to  mix  with 
the  contents  of  the  flask.  When  the  carbonate  is  com- 
pletely decomposed,  the  flask  is  placed  in  warm  water 
and  gentle  suction  applied  to  a  tube  passing  through  a 
perforated  cork  of  the  second  flask  till  all  the  carbonic 
acid  is  removed  ;  the  apparatus  is  then  allowed  to  cool 
and  is  again  weighed  ;  the  loss  of  weight  represents 
the  amount  of  carbonic  acid  ]}resent  in  the  salt  ex- 
amined. The  amount  of  carbonic  acid  thus  obtained 
is,  however,  somewhat  in  excess  of  that  existing  in  the 
form  of  carbonate  in  the  concretion,  since  some  of  it 
is  derived  from  tlie  combustion  of  the  organic  matter. 
155.  Intesfinal  concretions  are  found  chiefly 
in  the  caecum  and  large  intestines.  They  vary  consider- 
ably in  size  and  composition.  In  colour  they  are  yel- 
lowish, inclining  to  grey  or  brown  tints.  Their  nucleus 
is  usually  a  foreign  body,  a  gall-stone,  woody  fibre, 
fruit  stone,  etc.  Intestinal  concretions  having  a  defi- 
nite composition  consist  chiefly  of  ammonio-magnesium 
phospliate,  calcium  pliosphate,  carbonate  and  sulphate, 
organic  matter  and  fat.  The  analysis  of  these  calculi 
is  to  be  conducted  as  for  urinary  calculi  (Class  II.). 
They  should,  however,  always  be  extracted  with  ether, 
to  see  if  they  contain  cholesterin.     When  cax^bonate  of 


256  Clinical   Chemistry.  [Chap.  vi. 

magnesia  has  been  taken  habitually  it  may  accumulate 
and  concrete  in  the  intestines.  Concretions  of  yellow 
waxy  appearance  are  sometimes  passed,  varying  in 
size  from  a  pea  to  a  filbert ;  they  chiefly  consist  of 
fatty  matter  from  60  to  70  per  cent.,  mixed  with 
earthy  phosphates  (lime  and  magnesia)  and  an 
animal  substance  of  fibrinous  nature.  The  fatty 
matters  can  be  removed  by  ethei",  and  the  etherial 
solution  examined  to  ascertain  the  nature  of  the  fats 
as  directed  (§  99,  page  85).  The  organic  residue  or 
fibrinous  mass  will  give  the  reaction  with  hydrogen 
peroxide  (§  23) ;  the  earthy  phosphates  estimated  as 
directed  (§  113,  page  136) ;  the  lime  and  magnesia  as 
directed  (§§  84,  85,  pages  59,  60).  Other  concretions 
ma.y  consist  of  masses  of  hair,  woody  fibres,  and  husks 
of  seeds.  In  Lancashire  and  Scotland  concretions 
composed  of  the  caryopsis  and  fragments  of  the  en- 
velopes of  the  oat,  studded  or  encrusted  with  crystals 
of  triple  phosphate,  are  not  iincommon.  Concre- 
tions of  this  character  are  only  to  be  detected  by  a 
microscopical  examination.  Animals,  especially  the 
herbivora,  suffer  much  from  intestinal  concretions. 
In  Persia  and  Thibet,  peculiar  stones  termed  "  bezoar" 
are  met  with  in  a  species  of  antelope.  They  contain 
no  cholesterin,  and  yield  only  little  ash  when  burnt, 
and  seem  chiefly  to  consist  of  ellagic  acid,  an  acid 
related  to  gallic  acid.  It  is,  therefore,  probable  that 
these  concretions  are  derived  from  a  vegetable  source 
in  the  articles  used  for  diet. 

156.  Salivary  calculi  are  of  rare  occurrence  in 
man.  They  generally  occur  in  Whai-ton's  duct  near 
its  outlet,  where  they  may  be  easily  recognised.  More 
rarely  they  are  situated  deep  in.  the  main  duct  near 
the  gland  [Path.  Soc.  Trans.,  vol.  xxiv.,  p.  88).  The 
nucleus  often  consists  of  a  splinter  of  wood  or  a  frag- 
ment of  bone.  They  are  generally  of  rounded  oval 
form,  greyish-yellow  in  colour,  and  tuberculated   on 


Chap.  VI.]  Gouty  Concretions.  257 

the  surface.  Their  average  composition  is  :  Organic 
matter  and  Water,  13  ;  calcium  carbonate,  80  ;  calcium 
])hos2i}iate,  4;  and  magnesium  phospliateand  carbonate, 
3  per  cent.  For  analysis  proceed  as  directed  for 
pancreatic  calculi. 

157.  Proslatic  concretions  occasionally  form 
in  the  body  of  the  prostate  gland.  They  are  of  two 
kinds,  («)  very  small  rough  concretions  varying  in  size 
from  a  poppy  seed  to  a  mustard  seed,  extremely  nume- 
rous, of  yellowish  colour,  occurring  in  the  gland  before 
any  extensive  disorganisation  takes  place  ;  (6)  larger 
concretions,  of  ii'regular  and  porcelainous  appearance, 
generally  met  with  when  the  gland  is  gi*eatly  dis- 
integrated. The  former  variety  consists  of  calcium 
carbonate,  mixed  with  a  little  calcium  phosphate  ;  on 
section  they  exhibit  a  series  of  concentric  lines.  Their 
powder  ellervesces  strongly  on  the  addition  of  hydro- 
chloric acid,  and  yields  an  abundance  of  carbonic 
acid  gas.  The  acid  solution,  with  ammonium  oxalate 
added  in  excess,  throws  down  a  precipitate  of  calcium 
oxalate,  indicating  the  presence  of  lime ;  whilst  a  few 
drops  of  uranium  nitrate  solution  when  added  to  the 
acid  solution  throws  down  a  precipitate  showing  the 
presence  of  phosphoric  acid.  The  larger  concretions  con- 
tain less  carbonate  but  more  phosphate  of  lime  than 
the  smaller  ones.  It  must  not  be  forgotten  that  there  is 
always  a  danger  of  some  of  the  smaller  calculi  finding 
their  way  into  the  bladder,  and  thus  becoming  the 
nuclei  of  vesical  calculi. 

158.  Gouty  concretions.  Tophi.— Gouty  pei-- 
sons  are  subject  to  deposits  of  sodium  urate  encrusting 
the  surfaces  of  the  bones,  infiltrating  within  tendons 
and  their  .sheaths,  and  depositing  in  the  cartilages  of 
the  ear.  In  the  majority  of  cases  these  deposits 
lead  to  marked  deformities,  but  in  others,  though 
not  a  trace  of  external  deposit  may  be  perceptible, 
it  can  be  demonstrated  that  the  cartilages  and  other 

B 


258  Clinical  Chemistry.  [Chap.  vi. 

structures  of  the  joints  may  be  infiltrated  with  sodium 
urate.  Indeed,  Dr.  Garrod  insists  that  gouty  in- 
flammation is  invariably  attended  with  the  deposition 
of  sodium  urate.  Certainly  the  deposit  is  never  met 
with  in  acute  or  chronic  forms  of  rheumatism,  nor 
in  rheumatoid  arthritis ;  but  whether  an  attack  of 
gout  invariably  leads  to  the  deposition  of  sodium 
urate  is  a  point  that  requires  fui'ther  evidence 
before  it  is  finally  settled,  though  the  balance  of  evi- 
dence is  certainly  in  favour  that  it  is.  The  cases 
brought  forward  hitherto  to  disprove  it  were  not 
examined  so  completely  as  they  ought  to  have  been, 
and  minute  traces  are  easily  overlooked.  Before 
deciding  that  no  sodium  urate  is  deposited,  a  most 
searching  investigation  is  required  of  the  cartilage  and 
synovial  membranes,  since,  when  present  in  extremely 
small  quantities,  it  is  likely  to  escape  observation. 
When  first  deposited  the  sodium  urate  is  in  a  semi- 
fluid state,  but  it  soon  becomes  hardened  and  chalk- 
like. On  making  a  vertical  section  of  cartilage 
affected  with  this  deposit,  it  will  be  found  that  it  does 
not  extend  very  deeply,  rarely  exceeding  two-thirds  of 
its  depth.  The  deposit  appears  to  the  eye  amorphous, 
but  on  microscopic  examination  it  is  found  to  consist 
of  small  granules  mixed  with  crystalline  needles.  If 
the  cartilage  be  cut  into  thin  slices  and  washed  with 
cold  water  and  alcohol,  and  then  digested  in  hot  water, 
the  deposit  is  removed,  and  the  cartilage  becomes 
transparent.  The  aqueous  solution  being  evaporated, 
crystals  of  sodium  urate  will  be  deposited  in  small 
tufts.  Evaporated  with  nitric  acid  and  the  residue 
touched  with  ammonia,  they  give  the  purple  (murexide) 
reaction  of  uric  acid,  whilst  the  ash  left  after  incinera- 
tion with  the  blow-pipe  gives  abundant  evidence  of  the 
presence  of  soda.  These  deposits  are  said  to  have 
been  found  in  other  situations  besides  those  above 
enumerated,  as  in  the  lungs,  the  bronchial  tubes,  the 


Chap,  vi.j     Miscellaneous  Concretions. 


259 


meninges  of  the  brain,  and  in  the  concretions  on  the 
valves  of  the  heart  and  in  the  atheromatous  deposits 
in  the  aorta.  Dr.  GaiTod,  however,  has  failed  to  find 
the  least  trace  of  uric  acid  in  such  situations,  and 
suggests  that  tabular  crystals  of  cholesterin  may  have 
been  mistaken  for  that  body.  I  would  further  suggest 
that  the  chemical  test,  if  applied,  might  mislead,  since 
cholesterin  evaporated  with  niti'ic  acid  and  touched 
with  ammonia  gives  a  brownish-red  coloration  that 
might  be  mistaken  for  the  purplish  red  given  by 
uric  acid  with  this  test.  In  the  gouty  kidney 
white  points  and  streaks  are  to  be  seen  upon  the 
pyramidal  portion  of  the  kidney.  In  these  cases  the 
sodium  urate  is  generally  believed  to  be  deposited  in 
the  tubules,  but  Dr.  Garrod  thinks  that  it  is  embedded 
in  the  tibrous  structure  itself.  The  microscopical 
appearances  of  this  condition  of  kidney  are  admirably 
described  by  Dr.  George  Johnson,  in  his  woi'k  on 
diseases  of  the  kidney. 

159.  l^Iisccllaneous  concretions. — These  con- 
sist chiefly  of  varying  quantities  of  calcium  carbonate 
and  phosphate,  with  much  fatty  matter,  chiefly  cho- 
lesterin, fibrin,  casein,  gelatin,  etc.,  and  proteid  bodies. 
Such  are  the  pulmonary  concretions,  deposits  in  mus- 
cular tissues,  nasal  concretions,  etc.  The  following  are 
a  few^  of  the  recorded  analyses  giving  the  pei-centage 
amount  of  the  organic  matter  and  calcium  phosphate 
and  carbonate  : 


Solid 
tiunoiir 

from 
uterus. 


Ossified 
muscle. 


Coucre- 
tion 
from 
brain. 


Osteoid 

tumour 

from 

lungs. 


Nasal 
concre- 
tion. 


Organic        matter  "j 

and  water  j 

Calcium   phosphate 

Calcium    carbonate 


36 

56 
5 


58 

32-09 
S-GG 


22-46 

60-32 

17-21 


38-89 

53-33 

7-04 


5 

90 


In   a   concretion   taken  from   the   brain  of  a    horse, 


26o  Clinical  Chemistry.  [Chap.  vi. 

Lassaigne  found  58  parts  of  cholesterin,  39  "5  proteid 
matter,  and  2-5  of  calcium  phosphate  (Simon). 

160.  Products  of  deg'encration. — These  are 
generally  divided  into  two  classes.  Those  in  which 
there  is  a  direct  metaTnorjylwsis  of  the  proteid  elements 
of  a  tissue,  and  which  is  generally  followed  by  the 
destruction  of  the  histological  elements,  and  the  soften- 
ing of  the  intercellular  substance,  so  that  the  com- 
position and  structure  of  the  tissue  may  be  completely 
altered.  And  those  in  which  there  is  no  conversion 
of  the  pi'oteid  elements  themselves,  into  a  material  of 
another  kind,  but  the  new  substance  is  introduced 
from  without  by  the  blood  by  a  process  of  infiltration. 
Here  the  cell  elements  and  intercellular  substance  are 
not  softened  or  destroyed  to  any  great  extent,  and  even 
then  it  is  due  to  secondary  metamorphosis  produced 
by  the  infiltration,  as  the  fatty  changes  that  are 
associated  with  lardaceous  infiltration.  1.  Fatty  de- 
generation may  occur  either  as  an  infiltration  or  a 
metamorphosis,  but  no  decided  line  of  demarcation 
can  be  often  made  between  them,  since  the  same 
cause  may  be  in  action  at  the  same  time,  both  within 
and  without  the  tissues ;  and  also,  the  deposit  of  fat, 
having  accumulated,  may,  in  consequence  of  the 
pressure  it  occasions,  lead  to  fatty  metamorphosis  as 
well  In  fatty  infiltration,  when  the  process  is  dis- 
tinct, the  fat  is  deposited  in  oily  drops  within  the  cells. 
These  at  first  are  small  and  distinct,  but  as  the  process 
proceeds  they  accumulate  and  fill  the  cell,  obscuring 
the  muscles  and  protoplasm.  But  these  remain  un- 
altered, so  that  if  the  fat  is  removed  they  may  be 
restored  to  their  original  condition.  Fatty  infiltration 
occurs  chiefly  in  the  voluntary  muscles,  which  have 
been  disused,  as  in  paralysis,  joint  diseases,  lead  palsy, 
etc.  ;  in  the  muscular  tissue  of  the  heart,  and  espe- 
cially in  the  liver.  In  this  latter  instance  it  is  im- 
portant to  distinguish  it  from  the  acute  fatty  changes 


Chap.  VI. I  Fattv  Dr.GE.\'ERArioy.  261 

that  are  brought  about  by  the  action  of  certain  poisons, 
etc.  In  fatty  liver,  clue  to  infiltration,  the  organ  ia 
increased  in  size,  the  surface  is  smooth,  and  the  edges 
rounded.  The  section  pi-esents  an  opaque  ycllowish- 
wliite  colour,  in  early  stages  only  aflecting  the  portal 
area  of  the  lobules,  but  gradually  extending  to  the 
whole  lobule,  leaving  only  a  reddish  point  in  the 
centre,  at  the  origin  of  the  hepatic  vein.  Fatty  in- 
filtration is  a  chronic  process.  It  may  be  induced  by 
excessive  use  of  fatty  food  and  alcohol,  and  is  the 
frequent  result  of  chronic  wasting  diseases,  in  which  tlie 
oxvgenating  power  of  the  blood  is  diminished.  In  acute 
fatty  degeneration  of  the  liver  the  organ  is  diminished 
in  bulk,  the  surface  is  wrinkled,  and  the  edge  sharp. 
On  section  it  presents  a  yellowish-red  colour-,  which 
may  be  uniform  throughout,  or  else  mixed  with  patches 
of  brick-red  (Zenker's  patches).  The  lobules  have 
entirely  disappeared,  and  the  cells  consist  only  of  fat 
granules  and  debris.  The  process  is  acute.  It  is  met 
with  in  the  disease  known  as  acute  yellow  atrophy,  in 
phosphorus  poisoning,  after  the  injection  of  the  bile 
acids,  and  in  some  few  instances  it  has  been  found  in 
patients  dying  of  acute  diabetic  coma.  Fatty  infiltra- 
tion is  brought  about  by  excess  of  fat  in  the  blood ;  this 
may  be  simply  as  a  consequence  of  general  obesity,  or 
from  defective  oxydation,  which  accounts  for  the  fatty 
changes  which  are  associated  with  chronic  pulmonary 
disease,  especially  phthisis.  Fatty  degeneration  diftcrs 
from  the  preceding,  in  that  the  fat  is  not  derived 
directly  from  the  blood,  but  by  retrograde  changes 
taking  place  in  the  proteid  constituents  of  the  tissues 
themselves.  Extremely  minute  granules  of  dark  colour 
of  strong  refractive  power,  and  very  soluble  in  ether, 
first  ditluse  through  the  protoplasm.  As  the  process 
continues,  the  nucleus  is  invaded  and  the  cell  wall 
disappears.  The  granules  at  first  are  more  or  less 
coherent,    forming    rounded    masses     (corpuscles    of 


262  Clinical  Chemistry.  [Chap.  vi. 

Gluge) ;  but  after  a  time  these  break  down  and  the 
Efranules  are  distributed  through  the  tissue.  As  a 
result  of  fatty  degeneration  the  tissue  may  be  entirely 
destroyed,  or  the  fatty  product  may  be  absorbed,  or 
it  may  undergo  further  changes  and  become  caseous. 
Fatty  degeneration  may  attack  any  tissue  or  organ. 
In  the  arteries  and  capillaries,  as  a  primary  con- 
dition, fatty  degeneration  is  a  senile  change ;  but 
it  is  also  secondary  to  inflammatory  conditions  of 
the  vessels,  in  which  the  deposit  of  fat  is  preceded 
by  a  cellular  infiltration  of  the  subendothelial  con- 
nective tissue.  Fatty  degeneration  of  the  heai't 
may  be  diffused  or  localised.  The  former  may  occur 
in  the  course  of  those  diseases  in  which  oxydation  is 
reduced  to  a  minimum,  as  in  ansemia.  Dr.  Green 
(Trans.  Clin.  Society,  vol.  vui.,  1875)  instances  a  case 
of  acute  fatty  degeneration  of  the  heart,  induced 
by  profuse  loss  of  blood  during  the  menstrual  period 
and  inability  to  take  food.  In  a  minor  degree  fatty 
degeneration  of  heart  occurs  in  most  pyrexial  con- 
ditions. Localised  fatty  degeneration  of  the  heart 
is  generally  the  result  of  disease  or  obstruction  of 
the  coronary  arteries,  or  the  efi"ect  of  pericardial  in- 
flammation. Fatty  degeneration  of  the  brain  may 
be  either  acute  or  chronic.  In  the  former  it  is  gene- 
rally due  to  sudden  cutting  off"  of  the  blood  supply, 
as  for  instance  by  embolism  of  the  middle  cerebral 
artery.  In  chronic  softening,  the  supply  of  blood  is 
gradually  diminished  or  slowly  cut  off,  as  occurs 
when  the  vessels  are  diseased.  In  fatty  degeneration 
of  the  brain  a  considerable  amount  of  glycerin-phos- 
phoric acid  is  formed  among  the  products  of  dis- 
integration, occasioned  by  the  breaking  up  of  the 
phosphorised  fats,  lecithin,  etc.  Acute  fatty  degenera- 
tion of  the  liver  has  been  already  alluded  to.  The  epi- 
thelium of  the  kidney  undergoes  fatty  changes  after  at- 
tacks of  inflammation,  as  in  acute  and  chronic  nephritis, 


Chap.  VI.]  Fatty  Degeneration.  263 

and  also  in  acute  yellow  atrophy,  phosphorus  and  sul- 
phuric acid  poisoning,  and  in  some  cases  of  diabetes. 
More  fat  than  ordinary  is  found  in  the  epithelium  of 
persons  dying  from  chronic  wasting  diseases.  In  order 
to  investigate  the  nature  and  degree  of  the  fatty 
changes  in  any  given  tissue  we  first  determine  the 
aniDunt  of  fatty  matter  present,  the  neutral  fats,  the 
cholesterin  and  lecithin,  and  then  make  a  separate 
estimation  of  the  neutral  fats  to  ascertain  the  jiro- 
portionate  amounts  of  solid  and  oily  fat.  For  the  first 
determination,  a  weighed  portion  of  the  tissue,  finely 
divided,  is  to  be  dried  till  it  ceases  to  lose  weight.  It 
is  then  to  be  reduced  to  powder,  and  boiled  with  ether 
for  some  hours.  For  this  purpose  Drechsel's  fat  ex- 
hauster is  undoubtedly  the  best  form  of  apparatus,  but 
when  not  obtainable  the  following  method  can  be  satis- 
factorily emi)loyed.  The  finely-powdered  tissue  is 
introduced  into  a  glass  flask  and  half  filled  with 
absolute  ether.  The  mouth  of  the  flask  is  then  fitted 
with  a  perforated  cork,  through  which  a  fine  glass 
tube,  about  two  feet  long,  open  at  both  ends,  is 
introduced,  the  lower  end  of  which  should  only  be 
allowed  to  project  just  below  the  cork  into  the  flask. 
The  apparatus  is  suspended  by  means  of  a  support- 
stand  over  a  porcelain  basin,  so  that  about  one-third 
of  the  flask  is  submerged,  and  filled  with  hot  water 
about  twenty  degrees  below  boiling  point.  Over  the 
upper  third  of  the  flask,  and  about  half  way  up  the 
tube,  wrap  a  cloth  dipped  in  cold  water,  as  cold  as 
possible.  This  prevents  the  too  rapid  evaporation  of 
the  ether,  a  considerable  portion  of  which  condenses 
and  falls  back  into  the  flask.  The  temperature  of  the 
water  in  the  basin  is  to  be  maintained  by  the  constant 
addition  of  fresh  supplies,  as  it  is  advisable  not  to 
bring  a  flame  near  the  flask  containing  the  ether. 
After  the  ether  has  boiled  some  considerable  time, 
the  cork  with  the  tube  is  withdrawn,  and  the  etherial 


264  Clinical  Chemistry.  [Chap.  vi 

solution,  whilst  stUl  warm,  is  poured  into  a  weighed 
platinum  dish  and  evapox'ated.  In  order  to  remove  all 
traces  of  fatty  matter  from  the  flask,  it  should  be  rinsed 
with  a  little  absolute  ether,  and  the  rinsings  added  to 
the  solution  in  the  platinum  dish.  This  is  then  to  be 
weighed,  and  the  increase  of  the  weight  gives  the 
total  amount  of  fat.  In  order  to  estimate  the 
neutral  fats,  cholesterin  and  lecithin,  separately,  pro- 
ceed as  directed  §  99,  page  85.  If  it  is  desired  to 
ascertain  the  proportion  of  solid  fats  to  the  oily,  it  is 
necessary  to  dissolve  the  fatty  residue  thoroughly 
with  boiling  alcohol,  and  filter.  Boil  the  filtrate  with 
a  solution  of  potassium  hydrate,  which  saponifies  the 
fatty  matter.  The  mixture  is  then  evaporated,  and 
the  dry  residue  dissolved  in  water,  which  is  acidulated 
with  a  little  hydrochloric  acid.  On  cooling,  the 
stearic,  palmitic,  and  oleic  acids  will  be  deposited. 
These  ai-e  to  be  dissolved  in  boiling  alcohol,  and  some 
alcohoHc  solution  of  lead  acetate  added.  The  preci- 
pitate, which  consists  of  stearate,  palmitate,  and 
oleate  of  lead,  is  removed  by  filtration.  The  precipi- 
tate is  treated  with  hot  ether  (a),  which  removes  the 
oleate  of  lead,  whilst  the  filtrate  (6)  contains  the 
stearate  and  palmitate.  Both  the  filtrate  h  and  the 
etherial  solution  a  are  to  be  respectively  treated 
with  hydrochloric  acid,  and  the  mixture  warmed ;  the 
lead  is  then  to  be  removed  by  sulphydric  acid,  and 
the  precipitate  removed  by  filtration.  The  clear  fil- 
trates are  to  be  concentrated,  and  then  shaken  with 
ether,  and  the  etherial  solution  allowed  to  evaporate, 
when  from  a  oleic  acid  will  be  deposited,  and  from  6 
a  mixture  of  stearic  and  palmitic  acids  (the  solid  fatty 
acids)  will  crystallise  out. 

(2)  Lardaceous  degeneration,  or,  as  it  was  formerly 
termed,  amyloid  degeneration,  from  its  supposed  rela- 
tion to  starch  and  cellulose.  The  morbid  material  is 
deposited  in  the  first  instance  in  the  small  arteries 


Chap.  VI.]  LaRDACEOUS    DeGKNKKATION.  265 

and  capillaries,  cliielly  of  the  liver,  kidneys,  spleen, 
and  intestines,  though  all  organs  and  tissues  may 
be  invaded.  The  cells  of  the  intirna  are  the  first  to 
be  infiltrated  ;  thence  it  spreads  to  the  muscular  wall 
of  the  vessel,  and  from  thence  it  passes  to  the  cells 
and  intercellular  substance,  till  the  whole  organ  or 
tissue  is  involved.  It  is  still  a  question  among 
pathologists  whether  lardaceous  disease  is  a  true 
degeneration  (that  is,  a  chemical  and  structural  change 
in  living  tissues),  or  whether  it  is  an  infiltration  among 
the  tissues  of  a  morl)id  material  derived  from  the 
blood.  On  this  question,  the  histologists  generally 
support  the  view  that  it  is  an  infiltration,  the  patho- 
logical chemist  that  it  is  a  true  degeneration  of  tissue. 
When  first  discovered,  it  was  thought  to  be  analogous 
to  starchy  matter,  and  was  named  amyloid  ;  but  it  was 
soon  recognised  that  it  was  a  definite  nitrogenous 
body,  and  related  to  the  proteid  group,  and  the  term 
hirdacein  was  ajiplied  to  it,  to  express  the  waxy  or 
bacony  appearance  given  to  tissues  affected  by  it. 
With  regard  to  the  nature  of  this  substance  various 
views  have  been  expressed.  Dr.  Dickinson  regards  it 
as  de-alkalised  fibrin  ;  since  he  has  found  the  tissues  in- 
volved by  it  remarkably  deficient  in  potash,  and  has 
prepared  it  artificially,  by  digesting  fibrin  in  dilute 
hydrochloric  acid,  a  substance  which  gives  one  of  the 
reactions  supposed  to  be  characteristic  of  lardacein. 
In  objection  to  Dr.  Dickinson's  views,  it  may  be  urged 
that,  by  digesting  fibrin  in  dilute  hydrochloric  acid, 
syntonin,  and  not  lardacein,  is  formed  ;  whilst  the 
reaction  with  iodine,  as  I  showed  at  the  Pathological 
Society  {Trans.,  vol.  xxx.,  p.  536),  is  not  distinctive 
of  lardacein,  but  may  be  given  equally  with  dry  fibrin, 
with  syntonin,  and  with  casein.  This  is  important, 
since  the  red  colour,  being  developed  equally  with 
alkali  albumin  (casein)  as  with  acid  albumin  (syn- 
tonin), shows  that  the  reaction  is  not  caused  by  the 


266  Clinical  Chemistry.  [Chap.  vi. 

removal  of  an  alkali.  With  regard  to  the  deficiency 
of  potash  existing  in  the  affected  tissues,  that  may  be 
accounted  for  by  the  great  increase  of  fat  found  in 
them  ;  and  we  know  that  tissues  that  have  undergone 
fatty  degeneration  become  poorer  in  saline  constituents. 
The  view  I  am  inclined  to  adopt  is,  that  lardacein  is 
a  mixture  of  a  proteicl  with  a  fatty  body,  of  which  we 
have  a  physiological  example  in  vitellin,  and  which 
lloppe  Seyler  considers  to  be  a  mixture  of  globulin 
and  lecithin.  Lardacein  may  be  separated  from  the 
tissues  by  Kiihne's  process.  The  organ  is  finely 
minced,  and  extracted  repeatedly  with  cold  water,  and 
subsequently  with  dilute  alcohol,  till  the  fragments  be- 
come colourless.  They  are  then  digested  with  artificial 
gastric  juice.  This  has  no  action  on  lardacein,  but 
dissolves  all  the  other  proteids,  leaving  the  lardacein 
almost  pure,  with  the  exception  of  small  quantities  of 
elastic  tissue  and  mucin.  Lardacein  thus  obtained 
is  soluble  in  dilute  ammonia,  from  which  it  can  be 
precipitated  by  dilute  acids.  It  is  insoluble  in  water, 
and  does  not  perceptibly  swell  in  solutions  of  sodium 
chloride.  Strong  hydrochloric  acid  converts  it  into 
acid  albumin,  and  caustic  alkalies  into  alkali  albumin. 
Touched  with  an  aqueous  solution  of  iodine,  it 
acquires  a  brown-mahogany  colour,  whilst  methyl 
aniline  gives  a  rosy-red.  Formerly,  the  blue  colour 
produced  by  the  joint  action  of  iodine  and  sulphuric 
acid  when  poured  on  it  was  relied  on  as  a  test ;  but 
this  blue  coloration  was  shown  by  Dr.  John  Williams 
{Path.  Soc.  Trans.,  vol.  xxvii.,  p.  322)  could  be 
caused  by  the  admixture  of  iodine  and  sulphuric  acid 
alone,  without  the  intervention  of  any  other  sub- 
stance. 

Hyaline  degeneration. — At  the  debate  on  larda- 
ceous  disease  at  the  Pathological  Society,  1879,  Dr. 
Stephen  Mackenzie,  with  reference  to  the  influence  of 
fever  in  producing  the  disease,  called  attention  to  a 


Chap.  VI.]         Hyaline  Degeneration.  267 

cliange  in  the  blood-vessels  that  ocairred  in  certain 
diseases  with  blood  alterations.  He  had  fomid  it  in 
the  arteries  of  the  spleen  in  nearly  all  cases  of  pyaemia, 
in  some  cases  of  djal)etes,  in  a  case  of  angina  Ludo- 
vici.  Dr.  Klein  had  first  described  the  change  in 
typhoid  and  scarlet  fevers.  In  most  cases  the  change 
was  confined  to  the  intiina,  but  in  some  it  involved 
the  museularis.  It  consisted  in  a  hyaline  transforma- 
tion, which  did  not  give  a  characteristic  I'eaction  with 
iodine,  but  stained  slightly  with  methyl  aniline.  Dr. 
Mackenzie  did  not  regard  the  change  as  lardaceous, 
but  thought  an  examination  into  the  nature  of  the 
change  might  throw  some  light  upon  that  disease.  In 
commenting  on  Dr.  Mackenzie's  remarks,  I  suggested 
that  the  difference  between  hyaline  and  waxy  dege- 
neration might  be  only  one  of  degree,  the  hyaline 
being  the  first  step  in  the  degenerative  process.  A 
microscopic  examination  of  the  hyaline  substance 
shows  that,  at  first,  it  consists  of  granules  of  an  albu- 
minous nature,  which  are  insoluble  in  ether ;  but,  in  a 
more  advanced  stage,  the  granules  are  distinctly  fatty 
and  soluljle  iii  ether.  From  this,  it  would  appear 
that  the  change  is  connected  with  fatty  degeneration. 
It  may  be,  therefore,  that  hyaline  changes  are  the 
first  step  in  a  process  which,  if  acute,  leads  to  fatty 
degeneration,  if  chronic,  to  waxy  or  lardaceous 
disease. 

The  amyloid  bodies,  corpora  aviylacea  of  Kolliker 
and  Purkinje,  are  rounded  oval  bodies,  varying  in 
size  from  extremely  minute  granules,  which  refract 
light  strongly,  to  bodies  about  one  or  two  lines  in 
diameter,  formed  by  the  conglomeration  of  smaller 
granules,  apparently  in  a  succession  of  concentric 
layers.  They  are  most  frequently  found  in  the  bodies 
of  aged  persons,  chiefly  affecting  the  prostate,  the 
ependyma  of  the  ventricles,  the  fornix,  the  choroid 
plexus,  the  retina,  and  spinal  cord.     They  are  apt  to 


268  Clinical   Chemistry.  [Chap.  vi. 

become  calcified,  and  in  this  form,  when  met  with  in 
the  nerve-centres,  constitute  the  so-called  "brain 
sand."  The  corpora  amylacea  usually  stain  a  deep  blue 
with  aqueous  solution  of  iodine.  Sometimes  a  drop 
of  sulphuric  acid  is  required  to  develop  the  reaction ; 
occasionally,  however,  the  iodine  gives  a  greenish  or 
brownish  tint,  owing  to  the  admixture  of  nitrogenous 
matters.  These  bodies  undoubtedly  belong  to  the 
amylaceous,  or  starchy,  group,  and  seem  to  resemble 
cellulose  in  their  general  characters.  They  are  not  to 
be  confounded  with  lardacein,  which  was  unfortunately 
termed  amyloid  substance  when  first  investigated, 
from  a  misconception  of  its  real  nature. 

(3)  Mucoid  and  colloid  degeneration. — These  two 
forms  are  often  associated  together,  and  at  all  times  it 
is  difficult  to  draw  a  rigid  distinction  between  them. 
In  mucoid  degeneration  the  intercellular  substance  is 
chiefly  affected,  in  colloid  degeneration  the  cells.  In 
the  foi'mer  there  is  an  increase  of  mucin  in  the  con- 
nective tissue  elements,  in  the  latter  the  gelatinous 
constituents  have  apparently  undergone  changes,  and 
seem  to  be  converted  into  collagen,  and  perhaps  into 
semi-glutin  and  hemi-collin.  Mucin  is  found  normally 
in  the  adult  in  small  amount  in  all  connective  tissues 
proper;  in  the  embryonic  comiective  tissue  it  exists  in 
much  larger  quantities,  the  umbilical  cord  of  foetus 
yielding  it  to  a  gi-eat  extent.  It  is  also  derived  from 
the  secretion  exuded  by  epithelial  cells  (mucus),  and 
can  be  obtained  in  sufficient  quantity  for  examination 
from  the  saliva  (§  131,  page  175)  and  bile  (§  139, 
page  198).  In  normal  urine  it  is  present  in  small 
quantities,  which  is  much  increased  in  catarrhal 
conditions  of  the  renal  and  urinary  organs.  Mucin  is 
soluble  in  alkaline  solutions,  from  which  it  is  pre- 
cipitated by  acetic  acid.  Mucin  is  not  digested  by 
gasti-ic  juice,  but  is  by  the  pancreatic  ferment.  It  is 
not    precipitated    by    potassium     ferrocyanide    with 


Chap. VI.]  Mucoid  Degeneration.  269 

acetic  acid,  nor  by  tannic  acid.  Solutions  of  mucin 
with  alkaline  copper  solutions  prevents  the  precipita- 
tions of  cupric  hydrate,  and  no  reduction  takes  place 
on  boiling.  Collagen  is  the  name  given  to  a  substance 
obtained  from  the  white  fibres  of  connective  tissue, 
and  of  which  they  are  principally  composed.  It  can 
be  obtained  toleral)ly  pure  by  digesting  finely  sliced 
tendon  in  water  for  some  days.  Then  filter  off  precipi- 
tate, and  digest  precipitate  for  some  days  in  dilute 
baryta  water  ;  filter*,  and  wash  the  insoluble  residue 
thorougldy  in  water,  then  with  dilute  acetic  acid,  and 
again  with  water.  Hofmeister  has  shown  that  when 
gelatin  is  heated  for  some  tiuie  at  130"  0.  it  loses 
water  and  becomes  converted  into  a  substance 
resembling  gelatin ;  and  also  when  collagen  is  boiled 
for  more  than  twenty-four  hours  a  further  change 
occurs,  the  collagen  taking  up  water  and  becoming 
converted  into  two  peptone-like  bodies,  to  which  the 
names  semi-glutin  and  hemi-glutin  have  been  given. 
Hofmeister  represents  the  changes  by  the  following 
equations  : 

Gelatin.  Collagen. 

^10:i-"-161-'-^  31^39   ~    xlvO      =      ^-^i02tl-i49JN3iU38  j 

and 

Collagen.  Semi-glutin.  Hemi-glutin. 

C.02H149N31O3,  -f  3H,0  =  C^H^N,A2  +  C,,H™N,,0„. 

Professor  Gamgee  *  states,  that  whilst  mucin  is  un- 
questionably a  product  of  the  difierentiation  of  the 
protoplasm  of  certain  animal  cells,  and  is  obviously 
derived  from  the  proteids,  it  is  conceivable  that  it 
may  result  also  from  a  decomposition  in  which 
collagen  and  mucin  originate.  What  the  nature  of 
the  decomposition  may  be  is,  however,  quite  unknown. 

*  "  Physioloigcal    Chemistry   of    the  Animal   Body,''    p.    259. 
Macmillan. 


270  Clinical  Chemistry.  [Chap.  vi. 

A  further  study  of  tlie  subject  is  mucli  to  be  desired, 
as  likely  to  throw  considerable  light  on  the  pathology 
of  this  degenerative  process,  especially  with  regard  to 
the  chemistry  of  the  contents  of  the  ovarian  cysts. 
Professor  Ganagee's  account  of  these  bodies  is  the  best 
summary  extant  of  the  work  that  has  been  done  in  this 
direction.  Still,  there  must  be  further  investigation 
in  the  physiological  laboratory  before  the  results  can 
be  made  available  for  clinical  purposes.  Anybody 
taking  up  the  subject  from  its  present  standpoint 
would  find  a  field  for  original  research  likely  to 
yield  important  results.  At  present,  clinically,  we 
distinguish  between  mucoid  and  colloid  degeneration 
by  the  fact  that  in  the  former  case  the  fluids  are 
precipitated  by  acetic  acid  ;  in  the  latter,  not.  Mucoid 
degeneration  is  by  no  means  common,  and  seems  to 
imply  a  retrograde  metamorphosis  of  the  connective 
tissue  elements  to  their  embryonic  state.  It  occurs 
occasionally  in  the  intervertebral  and  costal  cartilages 
of  old  people  ;  it  sometimes  attacks  the  bones  and 
serous  membranes.  When  localised,  the  softened 
part  surrounded  by  the  firmer  normal  tissue  gives 
rise  to  a  cyst-like  formation.  In  an  important  com- 
munication to  the  Royal  Medical  and  Chirurgical 
Society  (Trans.,  vol.  Ixi.,  p.  57)  Dr.  W.  M.  Ord, 
describing  the  "  cretinoid  affection '"'  occasionally 
observed  in  middle-aged  women,  proposed  that  the 
term  myxoidemoj  should  be  applied  to  express  the 
essential  condition  observable  in  that  affection.  That 
condition  relates  to  the  jelly-like  swelling  of  the 
connective  tissue,  chiefly,  if  not  entirely,  consisting  of 
an  overgrowth  of  the  mucus-yielding  cement  by  which 
the  fibrils  of  the  white  element  are  held  together.  In 
one  of  Dr.  Ord's  cases  the  amount  of  mucin  obtained 
was  more  than  a  fiftieth  of  the  quantity  obtained  from 
the  skin  of  non-oedematous  bodies.  The  method 
employed  by  Dr.  Oranstoun  Charles,  who  made  the 


Chap.  VI.)  Mucoid  Degeneration.  271 

cheinifal  analysis  for  Dr.  Orel,  is  given  here,  as  it 
may  be  suitably  employed  for  similar  investiga- 
tions. The  skin  of  both  feet  was  cut  into  pieces, 
and  divided  into  three  nearly  equal  portions,  «,  &, 
and  7.  («)  was  digested  with  water  for  several 
days ;  the  filtrate  from  this  was  treated  with  an 
excess  of  acetic  acid,  let  stand  some  hours,  the  pre- 
cij^itate  separated  on  a  filter  and  washed  first  with 
water  acidified  with  acetic  acid,  and  then  with  pure 
water.  This  washed  precipitate  was  next  left  for 
twenty-four  hours  in  lime-water,  the  solution  filtei*ed, 
and  the  precipitate  again  thrown  down  by  excess  of 
acetic  acid.  To  purify  the  precipitate  thus  obtained 
it  was  washed  successively  with  acidified  water,  pure 
water,  alcohol,  and  ether,  and  then  di'ied  over  a  water- 
bath.  The  process  is  that  employed  by  Eichwald  for 
the  separation  of  mucin  from  Helix  pomatla  and  from 
tendons  {Ann.  ChejM.  PJtarm,.,  Bd.  134,  s.  177). 
(ys)  was  left  in  metliylated  spirits  for  three  days,  in 
lime-water  for  two  days,  then  filtered,  and  to  the 
filtrate  acetic  acid  added  in  excess.  Tlie  precipitate 
was  separated  and  purified  as  in  a.  (7)  was  digested  at 
once  with  dilute  baryta  water,  the  dissolved  mucin 
precipitated  by  acetic  acid,  and  pui'ified  as  before. 
The  body  obtained  by  the  above  three  methods  was 
sensibly  the  same  in  each  case  in  properties  and  in 
appearance,  and  nearly  eq  ual  in  amount ;  it  corre- 
sponded in  its  reactions  to  the  mucin  of  Scherer, 
Eichwald,  and  Staedeler.  Mucoid  degeneration  also 
affects  new  formations  ;  thus,  enchondromatous,  lijDO- 
niatous,  and  sarcomatous  tumoui's  may  undergo 
mucoid  transformation,  and  may  become  wholly  or 
partially  converted  into  myxomata.  In  colloid  de- 
generation the  process  commences  appai-ently  in  cells, 
and  not,  as  in  mucoid  degeneration,  between  the  white 
fibres  of  the  connective  tissue  element.  The  cells 
become  filled  with  small  masses  of  jelly-like  material. 


2)2  Clinical  Chemistry.  [Chap. vi. 

which  pushes  aside  the  nucleus,  and  at  length  destroys 
the  cell ;  after  a  time  the  intercellular  substance 
atrophies  and  softens.  In  many  cases  a  true  mucoid 
degeneration  of  the  intercellular  substance  seems  to 
follow  the  colloid  infiltration  of  the  cells.  This  gives 
additional  weight  to  Professor  Gamgee's  supposition 
that  mucin  and  collagen  originate  from  a  decom- 
position common  to  both. 

(4)  Calcareous  degeneration,  or  the  infiltration  of 
the  tissues  with  calcareous  particles.  May  be  either 
general,  as  the  result  of  an  accumulation  of  cal- 
careous salts  in  the  blood — for  instance,  as  in  osteo- 
malacia, where  the  earthy  salts  are  removed  from 
the  bone,  and  are  often  in  part  deposited  in  other 
tissues,  the  lungs,  stomach,  or  intestines.  Or  the  in- 
filtration may  be  local,  due  to  changes  in  the  tissue 
itself  following  some  impairment  of  their  nutrition ; 
or  as  a  consequence  of  a  retardation  or  diminution  of 
the  amount  of  blood  flowing  through  them,  as  I  have 
e]ideavoured  to  show,  may  be  one  of  the  causes  lead- 
ing to  calculous  deposit  in  the  tubules  of  the  kidney 
(page  240).  The  cause  of  calcareous  deposit  in 
tissues  has  been  explained  to  arise  from  the  stag- 
nation of  the  nutritive  fluids,  owing  to  which  the 
free  carbonic  acid  which  holds  the  earthy  salts  in 
solution  are  precipitated,  and,  the  circulation  through 
the  part  being  retarded^  these  insoluble  elements  are 
only  partially  removed,  and  so  become  deposited.  The 
ossification  of  arteries  proceeds  from  this  cause.  Cal- 
careous deposits  consist  chiefly  of  calcium  carbonate, 
calcium  phosphate,  magnesium  phosphate,  traces  of 
soluble  salts,  and  generally  fatty  matters  and  choles- 
terin.  For  their  chemical  examination,  exhaust 
thoroughly  with  ether,  to  remove  fatty  matters,  and 
proceed  to  estimate  the  earthy  matters  according  to 
the  directions  given  for  the  analysis  of  urinary  calculi, 
Class  II.  (§  152,  page  248). 


Chap.  VI.J  Pus.  273 

161.  Iflorbid  exudations. — (1)  Pus  is  a  patho- 
logical fluid,  and  consists  essentially  of  a  liquid 
portion,  "  liquor  puris,"  wliich  is  exuded  lic^uor  san- 
guinis, and  wliitt^  cor))uscles,  or  leucocytes,  which 
cannot  bo  distinguished  from  the  white  corj)UScles  of 
the  blood.  The  pus  corpuscles  can  be  separated  from 
the  liquor  puris  by  tlie  addition  of  a  10  per  cent, 
solution  of  sodium  chloride,  and  the  precipitated 
mass  removed  by  filtration,  and  thoroughly  washed 
with  the  same  solution  till  quite  free  from  serum. 
The  pus  corpuscles  are  spherical,  irregular  bodies, 
al)out  y'sVtt^^^  ^<^  3  /o  otli  of  an  inch,  or  8;^  to  10/^  in 
diameter,  containing  a  number  of  granules  and  one 
or  more  nuclei.  When  treated  with  dilute  acetic  acid, 
they  swell  up,  and  become  more  transparent,  and  the 
nuclei  more  distinct.  Treated  with  ammonia  or 
potash  solutions,  pus  becomes  tenacious  and  jelly-like. 
This  character  distinguishes  it  from  mucus,  which 
becomes  less  tenacious  and  more  fluid  on  the  addition 
of  these  solutions.  According  to  Miescher,  the  nuclei 
of  the  pus  corpuscles  contain  a  definite  organic  body, 
containing  phosphorus,  which  he  calls  nuclein.  This 
substance,  he  holds,  can  be  obtained  from  all  cells 
where  nuclei  exist.  It  is,  however,  doubtful  whether 
it  is  a  definite  compound,  since  the  results  obtained  by 
analysis  by  different  obseiwers  vary  considerably.  It 
is  more  probable  that  it  is  an  ordinary  proteid  sub- 
stance, combined  with  lecithin  or  other  phosphorised 
bodies,  in  varying  propoi-tions.  Eichwald  has  also  found 
peptone-like  bodies  in  purulent  fluids.  The  amount  of 
water  and  solids  present  in  pus  varies,  of  course,  with 
the  nature  of  the  pus.  Thus,  in  ichorous,  muco,  or  sero- 
pus,  the  solids  are  diminished.  The  following  is  an 
analysis  of  laudable  pus,  the  result  of  acute  inflamma- 
tion :  Water  87,  Solids  13,  in  100  ;  proteids  8 -5,  fatty 
matters  3'0,  extractives  0'7,  inorganic  residue  0-8. 
The  proteids  are  sero-albumin  and  paraglobulin.  The 
S 


274  Clinical  Chemistry.  [Chap.  vi. 

fatty  matters  consist  of  neutral  fats,  cholesterin,  and 
a  body  yielding  glycerin  phosphoric  acid,  probably 
lecithin,  but  some  consider  it  to  be  protagon.  The 
extractives  contain  traces  of  urea  and  glucose,  some- 
times leucin  and  tyrosin.  A  blue  colour  is  often 
noticed  on  the  dry  bandages  and  linen  which  have 
been  in  contact  with  pus ;  this  is  due  to  pyo-cyanin. 
This  substance  can  be  obtained  in  a  crystalline  form 
by  soaking  the  stained  linen  in  water,  containing  a 
few  drops  of  ammonia,  for  some  hours,  and  then 
filtering  ofi"  and  evaporating  the  green  liquid.  The 
concentrated  filtrate  is  then  agitated  with  chloroform, 
and  the  chloroform  solution  removed  and  treated  with 
very  dilute  sulphuric  acid,  and  the  mixture  allowed  to 
stand  for  some  time.  At  length  a  red  aqueous  layer 
separates,  which  is  removed  and  treated  with  caustic 
baryta  till  the  solution  becomes  blue ;  filter,  and 
agitate  the  filtrate  with  chloroform ;  remove  the 
chloroform  :"'*^jt'on,  and  allow  it  to  evaporate  spon- 
taneously, when  pyo-cyanin  will  crystallise  out  in 
bluish-coloured  needles  or  rectangular  Hakes.  The 
crystals  are  soluble  in  water  and  chloroform,  insoluble 
in  ether.  Acids  turn  their  solutions  red,  but  alkalies 
restore  the  blue  colour ;  chlorine  decolorises  both 
solutions.  The  researches  of  Liicke  and  Fitz  seem  to 
prove  that  pyo-cyanin  is  generated  by  a  bacillus, 
which,  according  to  the  latter  observer,  has  the  power 
of  decomposing  glycerin,  in  the  presence  of  calcium 
cai-bonate,  with  the  formation  of  carbonic  acid,  butyric 
acid,  and  hydrogen.  It  is  probably  the  same  bacillus 
that  sometimes  gives  milk  its  blue  colour. 

From  the  chloroformic  solution,  after  the  removal 
of  the  pyo-cyanin,  minute  yellow  crystals  of  pyo- 
xanthin  can  be  obtained  by  evaporation.  They  are 
coloured  red  by  acids,  and  violet  by  alkalies. 
Gelatin  and  chondrin  are  said  to  have  been  found 
in   pus,    but   their   existence    as    such    is    doubtful. 


Chap. VI.]  Dropsical  Fluids.  275 

Perhaps  the  peptone-like  boclias  described  by  Eichwald 
may  be  related  to  senii-glutin  and  henii-glutin  (page  269). 
The  inorganic  residue  consists  chieily  of  soluble  salts 
of  the  alkaline  chlorides,  nio.stly  as  sodium  chloride. 
The  earthy  salts  in  pus  derived  from  the  soft  tissues 
are  not  abundant;  but  iii  pus  derived  from  the 
neighbourhood  of  diseased  bone,  it  may  contain  as 
much  as  2-5  per  cent.  In  making  an  analysis  of  pus, 
the  paraglobulin  is  first  precijjitated  by  magnesium 
sulphate,  and  then  the  serum  all)uniin  coagulated  by 
heat  (§  98,  page  84).  The  liquid  is  then  to  be  agi- 
tated with  ether,  to  obtain  the  fatty  matters  (§  99, 
page  85) ;  and  then  the  extractives  are  to  be  separated 
by  the  methods  described  for  Urea  (§  100,  page  86), 
Glucose  (§  100,  page  88),  Leucin  (§  169,  page  126). 
A  fresh  portion  of  pus  is  then  incinerated,  and  the 
bases  and  acids  estimated  according  to  directions  at 
§  101,  page  93.  The  specific  gravity  is  taken  with 
the  specific  gravity  bottle  (§  92,  piee^66),  and  the 
reaction  determined  as  directed  §  9o,\^agc  67. 

(2)  Dropsical  flidds. — Whenever  the  balance  be- 
tween the  two  processes,  transfusion  of  the  nutritive 
plasma  from  the  blood-vessels  and  its  re-absoi-ption  by 
the  lymphatics,  is  disturbed,  the  quantity  of  paren- 
chymatous fluid,  which  is  always  present  in  small 
quantity  in  the  tissues,  becomes  increased.  This  dis- 
turbance of  pressure  of  the  fluid  in  the  blood-vessels 
and  that  in  the  parenchyma  may  result  from  general  or 
local  conditions.  In  general  dropsy,  such  as  we  find 
in  certain  diseases  of  the  kidnej-,  the  condition  de- 
pends on  hydrtemia,  especially  in  those  forms  where 
the  amount  of  water  passing  ofi"  through  the  kidneys 
is  lessened.  Thus,  general  dropsy  is  an  important 
clinical  symptom,  distinguishing  acute  tubal  nephritis, 
and  the  large  white  kidney  from  the  gi-anular  and 
the  albuminoid  kidney,  in  both  of  which  latter,  large 
quantities  of  dilute  urine  are  passed.     In  general,  the 


276  Clinical  Chemistry.  [Chap.  vi. 

dropsy  of  kidney  disease  depends  on  tlie  diminished 
action  of  the  kidneys,  so  that  the  water  ingested 
being  the  same,  its  exit  is  lessened ;  hence  the 
volume  of  blood  being  increased,  the  arterial  pres- 
sure is  augmented,  and  the  serum  passes  into  the 
tissues  in  consequence  of  the  increased  pressure, 
whilst  its  diluted  condition  perhaps  renders  it  more 
easy.  In  this  way  the  whole  of  the  tissues  of  the 
body  become  more  or  less  waterlogged.  When  the 
dropsical  effusion  is  localised,  as  in  ascites,  the  exuda- 
tion of  serum  depends  oil  mechanical  congestion  due 
to  venous  obstruction,  and  the  increased  pressure 
takes  place  in  the  veins,  and  thus  lessens  absorption 
by  the  lymphatics  and  veins.  In  the  dropsy  of  heart 
disease  both  forms  are  present.  In  diseases  of  the 
mitral  and  tricuspid  valves,  which  lead  to  dilatation  of 
the  right  side  of  the  heart,  obstruction  of  the  venous 
circulation  occurs,  and  increased  pressure  in  the  veins, 
which  is  at  first  most  noticeable  in  those  farthest 
from  the  centre  of  circulation,  and  which  from  their 
position  (the  lower  extremities)  allow  the  blood  more 
readily  to  stagnate  in  them.  But  diseases  affecting 
the  right  side  of  the  heart  also  induce  dropsy  by 
increasing  the  amount  of  water  in  the  blood,  since 
their  tendency  is  to  diminish  the  flow  of  blood 
through  the  kidney,  and  thus  to  diminish  the 
quantity  of  urine  secreted.  In  disease  of  the  aortic 
valves,  so  long  as  compensatory  hypertrophy  is 
maintained  dropsy  does  not  occur ;  but  so  soon  as 
the  left  ventricle  fails,  the  rapidity  of  the  circulation 
through  the  kidneys  falls,  and  the  quantity  of  urine 
excreted  diminishes,  so  that  the  quantity  of  water 
inci^eases  in  the  blood,  and  the  condition  of  hydrsemia 
is  induced.  It  will  be  thus  seen  that  dropsical  fluids 
are  blood  serum  more  or  less  diluted  with  water. 
This  is  an  important  point  to  remember;  for  if  on 
tapping  a  patient  we  find  the  amount  of  solids  in  the 


Chap.  VI.]  DkO/'S/CAL    FlUIDS.  277 

fluids  witlidnnvu  in  excess  of  tliose  noniially  present, 
wo  may  be  sure  tliafc  tlie  fluitl  is  not  au  ordinary 
dropsical  ctiusion,  and  contains  other  matters  beside.s 
.blood  serum.  The  specific  gravity  of  a  dropsical  fluid 
ranges  from  1"005  to  1'022,  according  to  the  amount 
of  water  present.  The  amount  of  jirotcids  contained 
in  it  are  variable,  ranging  from  0*4  to  6  per  cent. 
They  consist  of  ordinary  sero-albumin,  paraglobulin, 
and  fibrinogen.  Unless  withdrawn  from  inflamed 
tissues,  or  blood  is  present,  they  rarely  spontaneously 
coagulate,  biit  do  so  on  the  addition  of  fibrin  ferment,  or 
are  allowed  to  stand  some  time.  They  contain  only  a 
small  proportion  of  fatty  matters,  about  "05  per  cent., 
and  in  old-standing  cases  the  ether  extract  yields  chole- 
sterin.  The  extractives  are  urea,  a  variable  amount  of 
glucose,  and  sometimes  a  little  leucin.  The  spectrum  of 
sero-lutein  may  be  sometimes  obtained  by  allowing  the 
serum  to  stand  and  deposit,  and  then  filtering  it  till 
quite  clear.  The  clear  fluid  will  give  a  band  at  f;  and  a 
very  faint  one  between  F  and  G  (MacMunn).  The  salts 
are  those  of  the  blood.  The  exudation  occurring  in 
s[)ecial  serous  cavities  differs  little  from  that  poured  into 
the  subcutaneous  areolar  tissues.  Tliey  are,  perhaps, 
generally  richer  in  proteid  matters,  and  the  fluid  of 
the  pericardium  and  hydrocele  fluid  yields  a  larger  pro- 
portion of  fibrinogen.  The  latter  fluid  also  frequently 
contains  succinic  acid,  and  more  cholestei-in  than  is 
met  with  in  other  effusions.  The  cerebro-spinal  fluid 
is  accumulated  in  large  quantities  in  cases  of  sj^ina 
bifida,  and  chronic  hydrocephalus.  It  is  a  clear  fluid 
of  low  specific  gravity,  does  not  coagulate  when  heated, 
but  becomes  opalescent,  and  deposits  a  flocculent 
precipitate  on  the  addition  of  acetic  acid.  It  does 
not  contain  fibrinogen,  so  that  it  yields  no  coagulum 
when  fibrin  ferment  is  added  to  it.  Sugar  is  said  to 
be  genei-ally  present,  but  some  say  that  it  is  only  to 
be  found  when  there  is  irritation  or  inflammation  of 


278  Clinical  Chemistry.  [Chap.  vi. 

the  brain  or  spinal  cord.  It  is  to  be  regretted  that 
more  complete  analyses  of  this  fluid  have  not  been 
made.  It  is  a  question  that  occasionally  arises  in 
surgical  practice  [Med.  Clin.  Trans.,  vol.  ix.,  p.  247) 
whether  in  punctured  wounds  of  the  back  the  aqueous 
fluid  that  may  be  discharged  from  the  wound  comes 
from  the  cerebro-spinal  canal  or  from  injury  of  the 
kidney.*  In  the  case  Mr.  Holmes  brought  before  the 
Society  it  was  doubtful  whether  the  fluid  came  from  a 
wounded  ureter  or  from  the  cerebro-spinal  canal.  An 
analysis  of  the  fluid  Avhich  I  made  for  Mr.  Holmes 
gave  a  very  doubtful  result.  It  was  alkaline,  and 
contained  9 'So  parts  of  water  to  '15  of  solids.  The 
solids  consisted  of  an  ordinary  albumin  coagulable  by 
heat,  and  an  albumin  not  so  coagulable,  but  precipit- 
able  by  acetic  acid  ;  there  was  a  slight  greasy  residue 
left  from  the  evaporation  of  the  etherial  extract,  but 
no  cholesterin.  There  were  traces  of  urea,  -07  in  100 
parts,  but  no  uric  acid  or  glucose.  The  salts  consisted 
chiefly  of  sodium  chloride  '05  and  phosphates  'O-S  in 
100  parts.  The  amount  of  fluid  that  escaped  from 
the  wound  was  considerable,  three  large  draw-sheets 
being  soaked  in  the  course  of  the  day.  The  general 
character  of  the  fluid  was  not  unlike  that  from  a 
spina  bifida,  except  the  coagulable  albumin,  which, 
however,  might  have  come  from  the  wound.  The 
trace  of  urea  was  not  more  than  one  would  expect 
to  meet  with  as  an  extractive  in  a  fluid  of  this  char- 
acter, whilst  it  was  greatly  below  the  aiBount  found 
in  even  extremely  dilute  urine.  On  the  other  hand,  it 
is  difiicult  to  imagine  such  an  enormous  quantity  could 
have  escaped  from  the  cerebro-spinal  canal  for  such  a 
continued  period ;  and  again,  it  was  noticed  that  when 

*  "Section  of  the  renal  nerves  is  followed  by  a  most  copious 
secretion  by  what  has  been  called  hydruria  and  polyuria,  the 
iirine  at  the  same  time  frequently  becoming  albuminous." — 
Prof.  M.  Foster,  "  Textbook  of  Physiology,"  p.  274. 


Chap.  VI.]  Ovarian  Cysts.  279 

the  wound  was  partially  closed  the  urine  passed  by 
the  urethra  increased  in  quantity. 

The  liquor  amnii  and  allantoic  fluids  are  xisually 
clear  and  without  colour.  The  proportion  of  water  to 
the  solids  is  veiy  small.  They  contain  traces  of 
ordinary  albumin,  about  0*1  to  0-15  per  cent.,  but 
contain  no  fibrino-plastic  or  fibrinogen.  During  the 
early  period  of  gestation  they  contain  a  considerable 
amount  of  sugar,  which,  however,  gradually  disappeai's 
as  pregnancy  advances,  till  at  the  time  of  birth  every 
trace  has  disappeared.  {See  page  206.)  There  is  a 
variable  quantity  of  urea  always  present.  The 
allantoic  fluid  contains  a  characteristic  ingredient 
allantoiii  (§  67,  page  50).  The  inorganic  constituents 
of  both  fluids  consist  chiefly  of  sodium  chloride  and 
calcium  and  magnesium  phosphate. 

Synovia,  or  the  secretion  of  the  synovial  membrane 
of  joints,  is  denser  than  the  fluid  obtained  from  serous 
sacs,  and  more  viscid  from  containing  mucin.  (For 
the  systematic  examination  of  dropsical  fluids  see 
Ovarian  cysts,  page  282.) 

(3)  Contents  of  ovarian  cysts. — Considerable  differ- 
enoes  of  opinion,  especially  as  regards  the  chemical 
composition,  exists  as  regards  the  nature  of  their 
contents.  This  is  owing,  no  doubt,  to  tlie  want  of 
attention  being  paid  to  the  nature  of  the  degene- 
rative processes  that  produce  them.  Thus,  for 
instance,  we  have  in  some  cases  apparently  only  a 
sim])le  fluid,  poor  in  albumin,  of  low  specific  gravity, 
and  which  does  not  yield  fibrin  on  the  addition  of 
fibrin  ferment.  In  others  the  contents  are  viscid  and 
jelly-like,  rich  in  proteid  elements,  and  which  yield 
an  abundant  coagulum  with  fibrin  ferment ;  in  some 
of  these,  again,  mucin  will  be  found,  in  others  it  is 
absent,  and  we  have  instead  a  body  resembling 
collagen  or  gelatin.  It  was  formerly  thought  that 
paralbumin     and    metalbumin     were     characteristic 


28o  Clinical  Chemistry.  [Chap.  vi. 

constituents  of  ovarian  cysts,  biit  they  have  been 
found  in  the  contents  of  renal  cysts.  MacMunn 
believes  that  the  spectroscope  will  enable  us  to 
distinguish  the  contents  of  parovarian  and  ovarian 
cysts  from  other  fluids  resembling  them,  and  has 
described  the  spectrum  in  three  cases  of  parova- 
rian and  one  case  of  ovarian  fluid  that  gave  %he 
same  spectrum,  that  of  acid  hsematin ;  viz.,  a  band 
between  c  and  d,  nearer  c,  another  between  d  and 
E ;  on  adding  ammonium  sulphide  to  this  fluid  the 
bands  of  reduced  hsematin  appeared  at  once,  A  fifth 
specimen,  however,  gave  no  spectrum  whatever.  At 
present,  then,  we  have  no  one  characteristic  that  can 
enable  us  chemically  to  distinguish  between  the  fluid 
of  an  ovarian  cyst  and  the  contents  of  a  cyst  of 
another  organ.  If  the  solid  constituents  be  above  that 
of  ordinary  blood  serum,  we  can  say  positively  the 
fluid  is  not  ascitic,  but  otherwise  we  have  to  depend 
on  an  examination  of  the  whole  constituents  of  the 
fluid  before  we  can  venture  to  form  an  opinion.  The 
organic  matters  vary  considerably  from  -25  to  14'0 
per  cent. ;  the  inorganic  constituents,  however,  are 
tolerably  constant,  ranging  from  •!  to  "9  per  cent. 
The  proteid  substances  consist  of  ordinary  albumin, 
paraglobulin,  sometimes  of  fibrinogen.  Two  proteid 
bodies  paralbumin  and  metalbumin,  are  so  generally 
present  they  are  supposed  to  be  characteristic  con- 
stituents. Their  composition  seems  to  be  doubtful. 
Paralbumin  was  first  obtained  by  Scherer ;  its  alka- 
line solutions  are  ropy  and  viscid  ;  it  is  precipitated 
from  its  warm  solutions  by  carbonic  acid  gas,  but 
not  by  magnesium  sulphate ;  it  is  coagulated  by 
rdtric  acid,  but  the  precipitate  re-dissolves  in  strong 
acetic  acid.  It  seems  to  be  associated  with  a  body 
resembling  glycogen,  and  capable  of  being  converted 
into  a  substance  giving  the  reactions  of  dextrose 
with    copper.       Paralbumin    may  be   a   transitional 


Oiap.  VI.]  Hydatid  Cysts.  281 

form  of  mucin,  since  Eichwald  has  found  that  wlien 
hcatfd  with  dihite  mineral  acids,  mucin  yields  acid 
albumin,  and  another  body  which  closely  resembles 
dextrose  by  reducing  solutions  of  cupric  sulphate, 
Metalbumin  closely  resembles  paralbumin,  and  perhaps 
is  more  closely  related  in  its  reactions  to  mucin  than 
that  body.  Both  bodies  may  therefore  be  inter- 
mediate products  of  the  transformation  of  proteid 
substances  into  mucoid  or  colloid  matter.  Mucin  is 
found  in  some  cysts,  but  not  in  all ;  it  is  the  most 
variable  of  all  the  organic  constituents.  Ovarian 
fluids  yield  about  O'G  per  cent,  of  fatty  matter,  and 
sometimes  crystals  of  cholesterin  separate  out  and 
float  on  the  surface.  The  salts  do  not  differ  materially 
from  those  of  blood-ash.  The  fluid  from  hydatid  cysts, 
if  the  sac  be  not  inflamed,  is  limpid  Avhen  running 
from  the  cunnula,  but  becomes  opalescent  on  standing. 
The  reaction  is  alkaline,  and  the  specific  gravity 
ranges  from  1'009  to  1"013.  According  to  Murchison, 
the  fluid  of  the  hydatid  cysts  contains  no  albumin,  but 
Naunyn  has  found  traces.  If  to  the  contents  of  an 
hydatid  cyst  magnesium  sulphate  be  added,  and  then 
a  stream  of  COj  be  passed  through,  and  the  fluid  heated 
to  75*  C,  a  fine  precipitate  of  ])araglobulin  and  sero- 
albumin  will  generally  be  obtained  if  there  has  been 
inflammation  of  wall  of  the  cyst.  The  fluid,  how- 
ever, contains  no  urea.  The  great  chai'acteristic, 
however,  of  the  fluid  of  an  hydatid  cyst  is  the  con- 
siderable amount  of  sodium  chloride  it  contains,  a 
quantity  not  found  in  any  other  fluid  in  the  body 
whether  healthy  or  morbid.  These  characters,  even 
if  the  "  booklets  "  are  absent,  are  generally  sufficient 
to  determine  the  nature  of  the  fluid.  It  may,  how- 
ever, be  mistaken  for  the  fluid  from  hydro-nephrotic 
cysts.  This  is  of  low  specific  gravity,  1-004,  contains 
no  albumin  (paralbumin  and  cholesterin  have  been 
found  by  Dr.  Schetelig,  of  Hamburg,  in  a  renal  cyst). 


282  Clinical  Chemistry.  [chap.  vi. 

Urea  and  uric  acid  are  often  absent ',  the  reaction  is 
generally  faintly  acid,  more  frequently  neutral,  and 
although  containing  an  abundance  of  sodium  chloride, 
it  is  not  so  rich  in  this  salt  as  the  fluid  of  an  hydatid 
cyst.  The  method  of  procedure  for  an  analysis  of 
dropsical  or  ovarian  fluids  is  as  follows :  Evaporate 
a  weighed  portion  of  the  fluid  (§  92,  page  66)  to 
ascertain  proportion  of  water  and  solids,  and  the 
residue  incinerated  to  determine  the  saline  con- 
stituents (§  101,  page  93) ;  the  reaction  is  ascer- 
tained (§  93,  page  67) ;  the  proteids  are  determined 
by  precipitating  from  a  weighed  quantity  of  fluid  the 
paragiobulin,  and  fibrinogen  if  present,  by  precipita- 
tion with  magnesium  sulphate  (page  31) ;  remove 
precipitate,  and  acidulate  filtrate  with  a  few  drops 
of  dilute  acetic  acid,  and  coagulate  the  ordinary  al- 
bumin by  heat  (§  98,  page  84).  After  the  removal  of  the 
proteids,  evaporate  the  filtrate  to  dryness,  and  extract 
with  ether  to  remove  fatty  matter,  which  can  be 
estimated  according  to  directions  given,  §  99,  page 
85.  The  residue,  after  the  removal  of  the  ether, 
is  then  treated  successively  with  boiling  water  and 
boiling  alcohol,  and  the  aqueous  and  alcohoKc  extracts 
mixed  together  and  evaporated  to  dryness,  and  then 
dissolved  in  hot  water,  and  the  amounts  of  urea  and 
glucose  determined  by  processes  given  at  §  100,  pages 
87  and  88.  In  a  fresh  sample  of  the  fluid  examine 
for  special  products,  as  paralbumin,  metalbumin,  suc- 
cinic acid  ;  take  the  specific  gi-avity  according  to  di- 
rections §  92,  page  65  ;  examine  fluid  with  spectroscope 
for  bands  sero-lutein  (page  277),  or  ha?matin  (page  77). 
162.  Clieinical  chang:es  in  feone  chiefly  re- 
late to  the  variations  occurring  between  the  insoluble 
salts  in  relation  to  the  organic  basis.  Thus,  for 
instance,  in  the  atrophy  of  bones  met  with  in  cases 
of  long-standing  anchylosis,  dislocations,  etc.,  when 
the  compact  and  cancellous  tissue  gradually  becomes 


Chap.  VI.J 


JJlSJCASKS    OF  Bo.Mi. 


283 


absorl)C(l,  altliougli  tho  whole  bone  is  smallcT  and 
lighter,  y(!t  tlie  proportion  of  inorganic  constituents 
to  the  organic  is  relatively  more  than  in  lu  altliy 
bone.  The  same  occurs  as  the  result  of  chronic 
inllamniation  of  bone,  where  new  formation  of  osseous 
tissue  takes  place  in  the  enlarged  Haversian  central 
cancellous  spaces,  and  the  whole  bone  is  converted 
into  a  dense,  heavy  mass.  In  rickets  and  osteo- 
malacia, the  opposite  condition  maintains,  and  the 
bones  allected  have  their  calcareous  elements  dimi- 
nished. The  following  tables,  giving  analy.ses  of  the 
tibia,  will  best  show  the  composition  of  bono  under 
difierent  conditions  : — 

Analyses  or  Normal  Bone  (Tiiua). 


-eg     as 

8  2     -=5  >> 

11 

3  a 
Pl.o 

4) 

'^  2 

feS     Um 

0  ^ 

OP. 

^% 

d-^ 

W 

Or!:?!inic  matters 

! 

.10-37  i  43-42 

32-29 

31-97 

38-02 

41-16 

48-56 

Ciilciiini  pliosijbate 

53-43 

48-55 

59-74 

58-95 

52-93 

49-01 

41-77 

M;i;^nepiiiin  pbosi>liate  . 

2-00 

1-00 

1-34 

1-30 

0-25 

1-54 

0-87 

Ciilcium  ciarLioiaate . 

3-10 

5-79 

6-00 

7-08 

7-G6 

7-76 

7-10 

Soluble  salts    . 

1-07 

1-24 

0-G3 

1-55 

1-11 

0-52 

1-67 

Analyses  of  Morbid 

Bone.* 

m  5 

It 

la 

0   . 

la 

.Sj3 

9  A 

<spl 

A  'A 

°  a 

p^ '?; 

0  C3 

Sm 

r1  0 

h^ 

MHl 

!> 

R,'> 

0 

0 

Orgniiic  matter 

66-36 

75-69 

55-88 

4410 

48-55 

Calcium  pliosphate 

26-94 

18-83 

34-38  ) 
1-181 

48-20 

( 47-99 
1    1-55 

M.-isrut.'sium  pliosphate  . 

0-81 

0-54 

Calducu  carbonate 

4-88 

3-8:5 

6-63 

7-45 

1-00 

Soluble  salts  . 

1-08 

0-43 

1-91 

0-55 

0-91 

*  These  analyses  -were  made  from  typical,  but  not  exti-eme, 
instances  of  the  disease. 


284  Clinical  Chemistry.  [Chap.  vi. 

Bone  contains  less  water  in  proportion  to  its 
solids  than  any  other  tissue,  except  enamel  and  den- 
tine, pulverised  bone  evaporated  to  dryness  losing 
only  10  per  cent,  of  its  weight.  From  the  fact  that 
when  perfectly  dried  bone  is  placed  in  water  there  is 
a  slight  elevation  of  temperature,  it  is  supposed  that 
the  water  exists  in  bone  partly  in  a  state  of  chemical 
combination,  like  the  water  of  crystallisation.  The 
organic  matter  may  be  obtained  by  digesting  a  frag- 
ment of  bone  for  some  time  in  dilute  hydrochloric 
acid  (1 — 5),  when  the  inorganic  matters  will  be  dis- 
solved, leaving  the  gelatinous  matrix  intact.  This 
consists  of  a  body  identical  with  collagen  (which,  by 
long  boiling,  yields  gelatin,  and  gelatin  again,  by 
being  heated  above  boiling-point  (130°  C),  is  re- 
converted into  collagen)  mixed  with  a  small  quantity 
of  elasticin,  and  traces  of  proteid,  and  some  fat. 
Most  of  the  fat  of  bones,  however,  is  found  in  a  free 
state  in  the  yellow  marrow  of  the  medullary  cavity  of 
the  long  bones,  and,  to  a  lesser  extent,  in  the  red 
marrow  of  the  cancellated  tissue.  The  yellow  marrow 
differs  little  from  ordinary  fatty  matter,  and  consists 
chiefly  of  an  admixture  of  neutral  fats.  The  red 
marrow  yields  much  less  fatty  matter  than  the  yellow ; 
it  contains  a  proteid  body ;  a  free  acid  (lactic  acid  V), 
a  product  of  decomposition ;  hypoxanthin ;  and  cer- 
tain granules  which  stain  a  deep  blue  with  potas- 
sium ferrocyanide,  and  therefore  probably  contain 
iron.  In  addition,  there  are  large  multi-nucleated' 
cells  (^Myeloplaxes  of  Robin),  which  play  an  impor- 
tant part  in  the  absorption  and  formation  of  bone. 
These  and  the  granular  bodies,  according  to  Heitz- 
mann,  Malassez,  and  others,  have  also  to  do  with 
the  formation  of  the  red  blood  -  corpuscles.  In 
pernicious  anaemia  and  leucaemia,  where  nucleated 
coloured  corpuscles  similar  to  those  found  in  the  blood 
of  the  human  embryo  exist,  the  marrow  of  the  bones 


Cliap.  VI.]  AXALVSIS    OF   BoNE.  285 

is  also  generally  afTccted ;  hence  tlio  term  "  niyo- 
logciiic  l(Hic;i'inia."  The  inorganic  constituents  can  be 
obtained  l)y  incinerating  some  of  the  crushed  bone  in 
a  inuflie  furnace,  which  burns  off  the  organic  matter. 
In  addition  to  phosphoric  acid,  carbonic  acid,  and 
chlorine  in  combination  with  lime,  there  exists  a 
minute  quantity  of  fluorine,  about  0*22  parts  in  100 
of  bone-ash.  Some  of  the  other  metals  are  occa- 
sionally met  with,  as  strontium,  aluminum,  silicon, 
copjicr,  and  arsenic.  By  long  keeping,  bones  yield 
relatively  less  organic  matter  than  fresh,  but  their 
inorganic  constituents  are  little  altered.  Dr.  Norman 
Moore  has  {Path.  Soc.  Trans.,  1883)  shown  some 
interesting  si)ecimens  of  fossil  bone,  which  were 
evidently  from  a  subject  that  had  suffered  from 
chronic  rheumatic  arthritis. 

To  make  an  analysis  of  diseased  bone,  it  is 
advisable  to  take  a  section  representing  both  the  com- 
pact and  cancellated  part,  and  a  similar  section  in 
which  the  compact  part  is  carefully  divided  from  the 
cancellous,  and  submit  them  all  to  a  separate  analysis. 
In  this  we  learn  the  chemical  changes  that  have 
taken  place  in  the  bone  as  a  whole,  and  the  changes 
that  have  affected  the  compact  and  cancellous  portions 
respectively.  If  possible,  it  is  as  well,  from  the  same 
subject,  to  examine  a  portion  of  a  bone  as  nearly 
resembling  in  form  and  structure  the  one  diseased, 
but  which  is  apparently  free  from  the  disease.  The 
fragments  of  bone  are  to  be  reduced  to  a  fine  powder, 
and  the  weight  ascertained.  (Ten  grammes  is  a  con- 
venient quantity  to  take.)  The  powder  is  then 
placed  in  a  weighed  platinum  crucible,  and  dried  on  a 
calcium  chloride  bath  at  a  temperature  of  130°  C.  till  it 
ceases  to  lose  weight.  The  loss  of  weight  represents 
the  amount  of  water.  The  finely-dried  powder  is 
extracted  with  ether,  by  means  of  the  apparatus 
described  page  2G3 ;   this  gives  the  amount  of  fatty 


286  Clinical  Chemistry.  [Chap.  vi. 

matter;  and  the  etherial  residue  is  examined,  as  di- 
rected §  99, page  85,  to  determine  the  nature  of  the  fats. 
The  powder,  after  exhaustion  by  ether,  is  again  weighed 
in  the  weighed  platinum  crucible,  then  incinerated  in 
a  muffle  furnace  till  the  ash  is  quite  white,  allowed  to 
cool  over  sulphuric  acid,  and,  when  cold,  weighed. 
The  loss  of  weight  represents  the  organic  matter  ;  the 
actual  weight,  the  inorganic  residue.  The  ash  is  then 
boiled  at  100°  C.  in  distilled  water  for  some  time,  by 
which  means  the  soluble  salts  are  dissolved.  Filter, 
evaporate  filtrate,  and  weigh ;  the  weight  of  residue 
represents  weight  of  the  soluble  salts.  If  required, 
estimate  the  sodium  by  process  described  §  88,  page  61, 
and  the  hydrochloric  acid,  §  114,  page  136,  and  the 
carbonic  acid,  page  287.  The  insoluble  residue 
not  dissolved  by  boiling  water  is  then  dried  and 
weighed,  the  weight  representing  the  insoluble  salts. 
Dissolve  these  in  acetic  acid,  and  divide  the  solution 
into  two  equal  parts.  One  portion  of  the  solution 
is  then  examined  according  to  the  directions  given 
§§  84:,  85,  for  quantitative  determination  of  lime  and 
magnesia.  The  other  portion  is  heated  according  to 
the  directions  given  for  the  estimation  of  phosphoric 
acid  §  113,  and  for  hydrochloric  acid,  §  114.  Having 
obtained  the  total  amounts  of  sodium,  calcium,  and 
magnesium,  and  the  amounts  of  phosphoric  acid  and 
hydrochloric  acid,  the  result  of  the  analysis  is 
calculated  as  follows  :  The  amount  of  hydrochloric 
acid  obtained  by  the  aqueous  solution  is  combined 
with  the  sodium,  and  calculated  as  sodium  chloride, 
and  any  overplus  of  soda  is  combined  with  the  car- 
bonic acid  and  reckoned  as  sodium  carbonate.  The 
whole  of  the  magnesium  is  combined  with  phosphoric 
acid  as  magnesium  phosphate,  and  the  excess  of 
phosphoric  acid  is  deducted  from  the  original  amount 
of  phosphoric  acid  obtained  by  volumetric  analysis. 
This  is  combined  with   the   lime,   and  calculated  as 


Ciiap.  VI.]  AiVALVSIS    UF  BONE.  287 

calcium  phosphate.  But  as  it  is  insufficient  to  coui- 
bino  with  tlic  whole  of  the  lime,  the  amount  of  hydro- 
chloric acid  obtained  from  the  acid  solution  (not  from 
the  aquevous  solution,  which  has  been  combined  with 
sodium  to  form  sodium  chloride)  is  calculated  as 
calcium  chloride,  and  the  })ortion  of  the  lime  that 
still  remains  uncou\bined  is  then  taken  as  calcium 
carbonate.  The  fluorine  may  be  determined  either 
by  making  an  exact  determination  of  the  carbonic 
acid  existing  in  lime,  instead  of  assuming  that  the 
whole  of  lime  that  is  not  combined  with  phosphoric 
acid  and  hydrochloric  acid  as  given  above.  It  is  then 
found  that  a  minute  quantity  of  lime  is  in  excess  of 
what  is  required  to  form  calcium  carbonate,  and  this 
quantity  represents  the  amount  that  combines  to  form 
calcium  fluoride.  To  estimate  the  quantity  of  car- 
bonate lime,  a  weighed  quantity  of  unburnt  bone, 
finely  pulverised,  is  to  be  thoroughly  extracted  with 
boiling  water  to  remove  soluble  chlorides.  The 
residue  dried,  and  placed  in  a  glass  flask  fitted  with  a 
desiccating  tube  ;  a  test-tube  containing  hydrochloric 
acid  is  then  placed  in  the  flask,  so  arranged  that  by 
means  of  a  fine  wire  passed  through  the  cork  of  the 
flask  it  may  be  allowed  to  flow  gradually  over  the 
dried  portion  of  bone  at  the  bottom  of  the  flask.  The 
apparatus  and  its  contents  are  then  weighed ;  the 
hydrochloric  acid  is  poured  gentl}"-  over  the  powdered 
bone,  till  it  ceases  to  effervesce  on  addition  of  acid. 
The  flask  is  then  shaken  from  time  to  time  to  dis- 
engage any  gas  that  may  be  remaining,  and  afterwards 
weighed,  the  loss  of  weight  representing  the  amount 
of  carbonic  acid  in  combination  with  the  lime.  Now, 
by  the  previous  process  we  have  determined  the  total 
amount  of  lime  in  the  ash  of  bone,  and  have  found 
how  much  combines  with  the  phosphoric  acid,  how 
much  with  hydrochloric  acid,  and  now  we  have  found 
the  quantity  that  goes  to  form  calcium  carbonate  ;  the 


288  .  Clinical  Chemistry.  [Chap.vi. 

overplus  of  lime,  therefore,  that  remains  after  these 
calculations  may  be  reckoned  as  calcium  fluoride. 
The  determination,  however,  of  calcium  fluoride  is  of 
little  practical  value  in  clinical  or  pathological  investi- 
gations, so  that  the  direct  determination  of  the  calcium 
carbonate  need  not  necessarily  be  resorted  to ;  and  the 
analysis  of  bone  may  be  concluded  by  the  indirect 
determination  of  the  carbonate,  that  is,  by  the  pro- 
cess of  calculating  out  first  the  amount  of  lime 
combined  with  phosphoric  acid,  and  the  amount 
combined  with  hydrochloric  acid,  leaving  the  over- 
plus of  lime  to  be  calculated  as  carbonate.  The 
presence  of  fluorine  can  be  determined  by  treating 
large  quantities  of  the  ash  of  bones  with  strong 
sulphuric  acid,  and  gently  heating  the  mixture  in  a 
glass  vessel,  when  the  glass  will  become  corroded. 
If  the  glass  vessel  has  been  previously  weighed,  the 
amount  of  fluorine  can  be  determined  by  the  loss  of 
weight  the  glass  sustains. 

With  regard  to  the  chemical  changes  taking  place 
in  bone  in  rickets,  much  difi'erence  of  opinion  has  been 
expressed.  It  has  been  held  that  the  calcareous  salts 
are  not  retained,  owing  to  the  inability  of  the  organic 
matrix  to  fix  them ;  or  that  they  are  dissolved  out 
of  the  matrix,  owing  to  the  excessive  formation  of 
lactic  acid  in  the  system.  These  views  have  been 
based  upon  the  supposition  that  the  urine  contains  an 
excess  of  lime  salts.  This  is  based,  however,  on  very 
insufficient  evidence,  and  is  not  confirmed  by  the 
more  recent  analj^ses  of  urine  from  rachitic  patients, 
which  points  very  conclusively  to  the  fact  that  the 
lime  salts  are  not  excessively  excreted  by  the  kidneys 
in  this  disease.  Dr.  Seeman  {Zur  Pathogenese  und 
Etiologie  der  Rachitis;  Vir chow's  Archiv.,  Ixxvii., 
1879),  who  has  analysed  the  urine  of  sixteen  rachitic 
children,  has  actually  found  a  diminution,  which  was 
most  marked  when  the  disease  was  at  its  height.     It 


chnp.  VI.]      Rickets  and  Ostecvalac/a.  2S9 

is  proliablo  that  the  bone  changes  in  rickets  are  due  to 
a  lime  starvation  rather  than  to  a  lime  withdrawal ; 
the  salts  of  that  base  not  being  introdticed  in  sufficient 
quantity  into  the  system,  the  catarrhal  condition  of 
the  mucous  membrane  of  the  intestines,  which  invari- 
ably accompanies  this  disease,  hindering  their  absorp- 
tion. A  condition  termed  hsemorrhagic  rickets  has 
lately  been  described  ;  it  is  doubtful  whether  this  is 
related  in  any  way  to  scurvy,  or,  to  speak  more  accu- 
rately, the  result  of  a  scorbutic  condition,  or  is  merely 
an  exaggeration  of  the  hypera^mic  condition  of  the 
periosteum,  which  is  more  or  less  always  noticeable  in 
the  bones  of  rickety  children.  This  is  a  question  for 
histologists  to  decide,  but  it  is  an  interesting  fact  that 
these  cases  improve  under  the  administration  of 
lunc-juice.  In  osteomalacia  the  poverty  of  bone  in 
calcareous  constituents  evidently  depends  on  the  re- 
absorption  of  the  lime  salts,  since  not  only  does  the 
urine  demonstrably  show  an  excess  of  earthy  phos- 
phates, but  these  salts  are  also  deposited  in  the  tissues. 
(See  Calcai'eous  degeneration,  page  272.)  Some  have 
supposed  that  the  withdrawal  is  due  either  to  excessive 
formation  of  lactic  acid  in  the  system,  or  to  its  local 
formation  in  the  bone  itself.  The  fact  that  lactic 
acid  administered  in  large  quantities,  as  in  the  lactic 
acid  treatment  of  diabetes,  or  experimentally  in  the 
case  of  animals,  seems  to  show  that  excessive  forma- 
tion of  lactic  acid  is  not  the  cause.  It  is  probable 
in  this  case  that  the  process  is  truly  a  degenerative 
one,  like  myxoedema,  and  in  which  the  organic 
matter  of  the  bone  reverts  to  its  embryonic  con- 
dition, which  Morochowitz  believes  to  be  a  mixture 
of  collagen  and  mucin.  It  is  interesting  to  ob- 
serve, in  connection  with  its  probable  relation  to 
myxcedema,  that  it  most  frequently  attacks  women, 
at  about  the  same  age  when  myxcedema  makes  its 
appearance. 

T 


290  Clinical   Chemistry.  [Chap.  vi. 

Scurvy,  i^oiit,  a^nd  rlieumatism.  —  These 
diseases  may  be  considered  as  typical  examples  of 
disorders  arising,  in  the  first  instance,  from  chemical 
alterations  in  the  quality  of  the  blood.  In  their 
early  stages,  or  ill-defined  forms,  they  often  present 
many  features  common  to  each  other.  Indeed,  the 
close  resemblance  between  gout,  rheumatism,  and 
scurvy  in  their  early  stages  repeatedly  attracted  the 
notice  of  the  older  writers  on  the  subject.  Thus, 
Sydenham*  says,  "  where  matter  suited  to  produce 
the  gout  is  newly  generated  there  appear  various 
symptoms  which  occasion  us  to  suspect  the  scurvy, 
till  the  formation  and  actual  appearance  of  the  gout  re- 
move all  doubt  concerning  the  disordei". "  The  symptoms 
common  to  these  disorders  in  their  early  stages  may 
be  thus  briefly  enumerated.  Fugitive  and  erratic 
pains  in  the  limbs  ;  tenderness  of  the  joints  ;  attacks 
of  dyspnoea,  more  or  less  paroxysmal  in  character ; 
severe  attacks  of  pain  over  the  i-egion  of  the  heart ; 
weak  and  intermittent  pulse ;  irregular  discharge  of 
urine,  sometimes  profuse  and  of  low  specific  gravity, 
at  other  times  scanty  and  concentrated ;  and  a  ten- 
dency to  subcutaneous  haemorrhages  \  whilst  one  point 
in  common  to  these  symptoms,  worthy  of  especial  con- 
sideration, is  their  extreme  motility,  the  paroxysmal 
nature  of  their  onset,  the  suddenness  with  which  they 
disappear  or  transfer  themselves  from  one  region  or 
organ  to  another.  These  sudden  changes  afibrd  ad- 
ditional support  to  the  view  that  these  derangements 
are  caused  by  chemical  alterations  in  the  quality  of 
the  blood.  What  the  precise  nature  of  these  chemical 
changes  may  be  is  not  yet  definitely  established,  but 
evidence  is  gradually  increasing  which  points  more 
and  more  to  the  conclusion  that  they  arise  from  a 
diminution  of  the  normal  alkaline  reaction  of  the 
blood. 

•  "De  Eheumatismo,"  sect.  6,  cap.  v. 


Chap.  VI.]  ScuKyy.  291 

With  regard  to  scurvy,  the  most  important  ob- 
servations liave  been  made  by  Mr.  Busk  and  Dr. 
Garrod.  The  former,  in  a  series  of  analyses  of  blood, 
published  in  Dr.  G.  Budd's  article  on  Scurvy,  in  the 
"  Library  of  Medicine," showed  that  in  this  disease  there 
was  a  considerable  diminution  of  the  corpuscles  and 
increase  in  the  fibrin,  and  an  augmentation  of  the  in- 
organic residue.  Unfortunately,  Mr.  Busk  did  not 
complete  his  observations  by  making  a  separate  esti- 
mation of  each  of  the  inorganic  constituents.  In  ISiS, 
however.  Dr.  Garrod  found  that  in  the  urine  of  scurvy 
patients  the  potash  salts  were  considerably  diminished. 
This  observation  of  Dr.  Garrod  I  was  able  to  confirm 
in  1877.*  Dr.  Garrod  thought  that  this  diminution 
of  potash  was  due  to  a  deficiency  of  this  base  in  the 
food  of  those  affected,  but  it  has  been  subsequently 
shown  that  this  cannot  be  the  case,  since  peas,  which 
form  an  important  item  of  the  sailor's  diet,  are  rich  in 
this  substance ;  and,  moreover,  if  we  give  patients 
suffering  from  the  disease  unlimited  quantities  of 
Liebig's  extract  of  meat,  a  food  extremely  ricli  in 
potash  salts,  no  amelioration  occurs  till  lemon  juice, 
potatoes,  or  other  fresh  vegetable  substance  is  ad- 
ministered as  well.  This  suggests  that  scurvy  does 
not  depend  on  the  withdrawal  of  potash  from  the 
system,  but  on  some  alteration  subsisting  between  the 
organic  acids  and  the  base.  With  regard  to  this  point, 
I  was  able  to  establish  the  important  fact  that  the 
urine  passed  by  scorbutic  patients  was  deficient  not 
only  in  potash  but  also  in  the  alkaline  phosphates. 
Thus,  after  the  withdrawal  of  all  vegetable  food  for 
eighteen  days,  I  found  the  alkaline  phosphates  had 
sunk  from  2-1  grms.  to  1'5  grms.,  whilst  there  was  a 
slight  increase  of  the  earthy  phosphates.  Again,  in 
four  cases  of  scurvy,  two  of  which  are  related  in  my 

*  "An  Enquiry  into  the  General  Pathology  of  Scurvy."  Le-\vis, 
1877. 


292  Clinical  Chemistry.  [Chap.  vl 

pamphlet,  and  two  I  have  subsequently  observed, 
I  found  in  the  first  case  that  the  alkaline  phosphates 
on  admission  were  as  low  as  0'76  grm.,  but  that 
on  the  administration  of  lemon  juice,  the  diet  in  other 
respects  being  the  same,  they  rose  to  1  '6  grms.  In  the 
second  case,  the  amount  on  admission  was  0'57  grm., 
which  rose  after  administration  of  lemon  juice  to  1'6 
grms.  In  the  third  case  the  rise  was  not  so  marked, 
being  from  1'25  grms.  to  1'77  grms.;  and  in  the  fourth 
case  the  lemon  juice  increased  the  amount  from  0"87 
grm.  to  1  "29  grms.  In  all  these  cases  the  diet  was  the 
same  throughout,  the  only  difference  being  the  ad- 
ministration of  a  small  quantity  of  lemon  juice  (2  oz. 
daily),  which  could  not  possibly  account  for  the  de- 
cided increase  of  the  alkaline  phosphates.  It  therefore 
seems  to  me  that  these  salts  are  retained  in  the  system 
in  scurvy  to  supply  the  deficiency  of  the  other  alkaline 
salts,  the  alkaline  carbonates  and  bicarbonates,  which 
are  withdrawn  when  fresh  vegetables  are  withheld. 
This  view  is  in  accord  with  the  experiments  of  Hoff- 
mann and  Loscar,  to  which  attention  has  been  already 
called  {§  93,  page  68).  There  can  be  no  doubt  that 
the  alkalescence  of  the  blood  is  mainly  dependent  on 
the  formation  of  the  alkaline  carbonates  derived  from 
the  reduction  of  the  organic  salts,  the  lactates,  malates, 
citrates,  etc.,  introduced  with  the  food,  chiefly  by  vege- 
tables, but  also,  as  the  experience  of  Dr.  Neal  in  the  Eira 
Expedition  tends  to  show  {Med.  and  Chir.  Soc.  Trans., 
1883),  with  fresh  meat  as  well.  When  this  supply  is 
cut  off,  as  is  the  case  in  long  voyages  or  in  sieges,  etc., 
the  blood  is  deprived  of  one  of  its  sources  for  maintain- 
ing its  alkalescence  at  its  normal  point,  and  conse- 
quently it  falls  back  on  the  other  alkaline  salts,  viz., 
the  alkaline  phosphates,  to  supply  the  deficiency.  In 
this  way  it  may  maintain  the  proper  degree  of  alka- 
linity for  a  time,  but  after  a  while  a  minimum  point 
is  reached  which  is  incompatible  with  healthy  nutrition, 


Chap.  VI.]  SCURI'V.  293 

a,nd  textural  changes  are  the  result.  These  changes  in 
scurvy  re.sciiil)lc  closely  those  induced  in  animals,  iu 
whom,  by  feeding  with  food  rich  in  acid  salts,  or  by 
the  direct  administration  of  acids,  the  alkalinity  of  the 
blood  has  been  slowly  diminished,  viz.,  dissolution  of 
the  blood  globules,  ecchymoses  in  the  heart,  blood- 
stains in  the  mediastinum,  gums,  and  mucous  surfaces; 
■whilst  the  muscular  structure  of  the  heart  and  muscles 
generally,  as  well  as  the  secreting  cells  of  the  liver  and 
kidney,  become  granular  and  even  distinctly  fatty 
(§93,  page  09).  With  regard  to  the  influence  of  the 
oi-ganic  salts  in  the  prevention  of  scurvy,  it  is  inter- 
estmg  to  remark  that  their  range  is  apparently  limited. 
Experience  has  shown  us  that  fresh  vegetables  alone 
ai'e  eflicacious  as  anti-scorbutics,  and  the  same  may  be 
said  of  meat.  In  Arctic  regions,  where  the  meat  is 
frozen  almost  as  soon  as  killed,  and  in  hot  countries, 
where  it  is  eaten  before  the  changes  induced  by  rigor- 
uiortis  set  in,  meat  is  considered  as  highly  anti-scorbutic. 
In  Europe,  where  the  meat  is  generally  kept  some 
time  before  it  is  used  as  food,  it  is  not  so  reputed.  The 
exjilanation  of  this  lies  in  the  fact  that  fresh  vege- 
tables and  meat  undergo  changes  by  keeping  with 
regard  to  the  relation  of  the  organic  acids  to  the  bases. 
Thus,  the  juices  of  fresh  vegetables  contain  a  certain 
quantity  of  organic  acid  (malic,  citric,  tartaric,  etc.) 
in  combination  with  a  definite  quantity  of  a  base. 
On  keeping,  fermentative  changes  take  place  in  the 
saccharine  elements  (as  we  see  in  fodder  preserved  by 
ensilage),  and  an  additional  quantity  of  free  organic 
acid  is  foi'med  (this  in  the  case  of  vegetables  is  acetic 
acid),  whilst  the  quantity  of  the  base  in  the  vegetable 
remains  constant.  Now  this  additional  acid  takes  a 
portion  of  the  base  from  the  existing  salts,  reducing 
them  from  alkaline  or  neutral  salts,  with  three  or  two 
equivalents  of  base,  to  acid  salts,  with  only  one  equiva- 
lent.    These  acid  salts,  the  malates,  citrates,  acetates, 


294  Clinical  Chemistry.  [Chap.vi. 

etc.,  in  turn  are  reduced  in  the  blood  to  acid  carbonates 
(bicarbonates),  salts  which,  though  they  may  have  an 
alkaline  "reaction,  play  the  part  of  an  acid  in  the 
system,  and  effect  decompositions  with  neutral  salts  in 
all  respects  like  acids  (see  formulse,  pages  24,  70,  183). 
The  same  may  be  said  with  regard  to  meat,  since  after 
rigor  mortis*  has  set  in  there  is  an  increase  of  lactic 
acid  in  its  juices,  so  that  acid  instead  of  alkaline  lactates 
are  formed.  From  the  foregoing  it  will  be  gathered 
that  the  development  of  scurvy  depends  in  the  main 
on  a  change  in  the  conditions  of  the  blood,  in  the  di- 
rection of  a  diminution  of  its  alkalescence,  and  that 
this  diminution  may  be  caused  either  by  the  direct 
cutting  off  of  organic  salts  which  yield  by  oxydation 
alkaline  carbonates  in  the  blood  ;  or  indirectly,  though 
not  nearly  so  immediately,  by  the  continued  use  of 
food  which  contains  acid  instead  of  alkaline  salts. 
And  further,  that  this  change  in  the  composition  of  the 
blood  is  more  real  than  apparent,  since  the  acid  salt  is 
a  bicarbonate  of  potash  or  soda,  a  salt  which  has  an 
alkaline  reaction,  and  so  apparently  continues  to  give 
blood  its  alkaline  reaction,  whilst  its  chemical  consti- 
tution is  that  of  an  acid  salt,  and  acts  as  such  in  the 
chemical  decompositions  it  occasions  in  the  body.  It 
is  only  by  this  means,  as  we  have  seen  when  discussing 
the  nature  of  the  reaction  of  the  urine  and  the  gastric 
juice  (§§  107,  179),  that  we  are  able  to  account  for  the 
seeming  paradox  of  the  separation  of  these  acid  secre- 
tions from  the  alkaline  blood. 

*  It  has  been  pointed  out  as  an  objection  to  the  view  that  kept 
meat  has  no  anti-scorbutic  virtues,  that  the  South  American  hunters 
subsist  almost  entirely  on  dried  hung  meat.  So  that  if  scurvy  de- 
pended on  the  undue  development  of  acid  in  the  juices  of  the 
meat  after  having  been  killed  some  time,  these  men  ought  to  suffer 
from  scurvy,  whereas  they  are  remarkably  free  from  the  disease. 
It  is  probable,  however,  that  the  rapid  drying  of  the  freshly  killed 
meat  under  a  tropical  sun  j^uts  a  stop  to  the  fermentative  changes 
that  produce  excess  of  lactic  acid,  so  that  the  "jerked"  beef  of 
tropical  countries  resembles  the  frozen  meat  of  Arctic  regions. 


Chap.  VI.]  Gout.  295 

In  gout  a  diniimition  of  the  alkaline  reaction  of 
tlie  blood  has  also  b(!on  observed.  Dr,  Garrod  has 
pointed  out,  that  with  the  exception  of  collapsed 
cholera,  and  perhaps  certain  cases  of  albuminuria,  the 
reaction  of  the  blood  is  to  be  found  neunsr  the  neutral 
point  in  severe  forms  of  chronic  gout  than  in  any  other 
disease.  This  diminished  alkalinity  in  the  blood  of 
gout  has  a  relation  to  that  which  happens  in  scurvy, 
for  though  it  does  not  depend  on  the  actual  withdrawal 
of  alkaline  salts  supplied  by  fresh  fruits  and  vegetables, 
yet  the  diminution  is  caused  by  the  addition  of  acids 
or  acid  salts  taken  in  excess  with  the  food,  or  retained 
in  the  system,  the  result  of  imperfect  elimination,  etc. 
It  is  generally  held  that  the  excessive  formation  of  uric 
acid  is  the  reason  of  the  phenomena  observed  in  this 
disease,  but  the  idea  is  gaining  ground  that  the  pre- 
sence of  this  substance  in  the  blood,  and  its  deposit  in 
the  tissues,  is  not  caused  by  excessive  formation,  but  to 
the  fact  of  its  retention  in  the  system  and  to  its  insolu- 
bility. When  speaking  of  uric  acid  (§  111)  it  was 
stated  that  this  substance  is  never  found  in  normal 
blood,  or  perhaps  even  in  the  blood  of  any  disease 
except  gout,  and  it  is  considered  probable  that  in 
man  it  is  not  formed  in  the  body  to  the  extent  that 
had  been  supposed.  Indeed,  the  evidence  seems  to 
point  to  that  fact,  that  the  quantity  formed  in  health 
is  extremely  small,  and  that  it  is  desti'oyed  almost  as 
soon  as  formed,  and  so  never  enters  the  general  current 
of  the  circulation.  Whilst  the  small  quantity  (0'5  grm.) 
that  escapes  daily  by  the  kidney  does  not  probably  repre- 
sent the  amount  foi'med  in  the  body,  but  is  simply  the 
uric  acid  formed  by  the  kidney  itself,  and  which  passes 
directly  out  of  the  body  instead  of  being  destroyed.  In 
gout,  however,  we  have  decided  evidence  that  uric  acid 
is  present  in  the  blood,  that  it  is  deposited  in  certain 
tissues;  and  also,  although  the  evidence  is  not  quite 
satisfactory  to  me  that  even  the  small  quantity  of  uric 


296  Clinical  Chemistry.  [Chap.  vi. 

acid  "wliicli  appears  in  normal  urine  is  reduced.  Dr. 
Garrod  considers  gout  to  depend  upon  a  failure  of  the 
renal  function  to  excrete  uric  acid.  In  this  way  he 
accounts  for  the  diminution  of  uric  acid  from  the  urine 
and  its  accumulation  in  the  blood  ;  whilst  its  deposition 
in  the  tissues  depends  on  this  accumulation,  and  on  the 
fact  that  uric  acid  is  present  in  the  blood  in  the  form 
of  insoluble  urate  of  soda.  If  it  could  be  satisfactorily- 
proved  that  the  minute  quantity  of  uric  acid,  0*5  grm., 
constantly  present  in  healthy  urine,  really  came  from 
the  blood,  or  that  it  was  proved  beyond  doubt  that  this 
extremely  minute  quantity  was  still  further  invariably 
reduced  in  gouty  patients,  Dr.  Garrod's  view  might  be 
accepted  without  challenge.  But  thei-e  are  difficulties 
in  the  way  of  accepting  the  belief  that  the  uric  acid  of 
the  urine  comes  from  the  system  generally,  whilst  its 
diminution  in  gout  is  by  no  means  invariable  ;  for 
where  this  diminution  is  chiefly  observed  is  in  chronic 
cases,  where  kidney  changes  have  been  established. 
In  fact,  I  venture  to  think  the  accumulation  of  uric 
acid  in  the  blood,  and  its  deposit  in  certain  tissues, 
depend  on  other  conditions  than  failure  of  the  renal 
function,  and  that  the  first  step  in  the  process  lies  in 
the  failure  of  the  tissues  to  reduce  the  uric  acid  formed 
in  them,  as  is  the  case  in  health.  In  the  large  glands, 
or  where  the  current  of  the  circulation  is  free,  the  uric 
acid  is  carried  into  the  blood  and  gradually  reduced  to 
urea ;  in  tissues  outside  the  current  of  the  circulation 
the  insoluble  uric  acid  is  not  so  readily  carried  off, 
and  so  on  the  slightest  disturbance  is  deposited,  as  is 
the  case  in  cartilages  of  the  joints,  the  ear,  etc.  The 
conditions  which  prevent  the  normal  destruction  of 
uric  acid  in  the  tissues,  and  which  permit  it  to  pass 
into  the  circulation,  depend  probably  on  disturbance  of 
innervation.  These  conditions  I  have  endeavoured  to 
formulate  in  the  chapter  on  the  derangements  asso- 
ciated with  deposits  of  uric  acid,  in  my  work  "  On 


Chap.  VI.]  Gout.  297 

Morbid  Conditions  of  the  Urine"  (p.  65).  As  they  are 
too  lengthy  to  dwell  upon  here,  it  will  be  sufficient 
briefly  to  state  the  conelu.sions  arrived  at,  which  are  that 
the  first  step  in  the  pathology  of  gout  is  a  textural  de- 
generation, either  hereditary  or  acquired,  by  which  the 
tissues  and  blood  become  loaded  Avith  effete  products; 
that  such  predisposing  conditions  lead  at  last  to  a  dis- 
turbance of  some  special  troi)hic  nerve  centre,  caused 
either  by  a  degenerative  change  in  its  structure,  or  de- 
rangement of  its  functions  by  the  circulation  through 
it  of  impure  blood.  This  disturbance  may  be  con- 
sidered the  determining  cause  of  the  gouty  attack. 
The  restdt  is  the  accumulation  of  uric  acid  in  the 
blood,  and  the  deposition  of  urate  of  soda  in  the 
tissues. 

With  regard  to  the  diminished  alkalinity  of  the 
blood  noticed  in  chronic  gout,  although  no  doubt  in 
some  measure  due  to  the  presence  of  uric  acid  and  acid 
xirates,  yet  excess  of  other  organic  acids  undoubtedly 
has  to  be  taken  into  consideration.  For  if  the  acids 
concerned  in  the  production  of  gout  were  derived 
solely  from  the  nitrogenous  elements  of  the  food  and 
tissues,  then  by  a  rigid  limitation  of  animal  food  within 
physiological  limits  we  might  hope  to  check  or  control 
the  progress  of  the  disease.  But  other  articles  of  diet 
besides  the  nitrogenous,  or  those  which,  like  alcohol, 
disturb  the  functions  of  the  liver,  and  are  thus  sup- 
posed to  lead  to  increased  formation  of  uric  acid,  give 
rise  to  gouty  symptoms;  and  it  is  a  common  experience 
with  the  gouty  that  tliere  is  as  much  arthritic  trouble 
in  a  plateful  of  apple  tart  as  in  a  mutton  chop,  and  in 
a  few  strawberries  as  in  a  glass  of  port  wine. 

In  rheumatism,  no  observations,  as  far  as  I  am 
aware,  have  been  made  to  detei-mine  whether  there  is 
a  diminution  of  the  alkaline  reaction  of  the  blood  ;  but 
no  one  can  have  observed  the  enormous  quantity  of 
acid  poured  out  from  the  body  by  the  skin  in  this 


298  Clinical  Chemistry.  [Chap.  vi. 

disease,  or  have  noted  the  high  degree  of  the  acidity  of 
the  urine  during  the  progress  of  the  attack,  without 
coming  to  the  conclusion  that  an  excessive  formation  of 
acid  is  going  on  iia  the  system.  What  the  nature  and 
character  of  the  acid  is,  or  how  formed,  we  know 
absolutely  nothing,  though  some  have  supposed  it  to 
be  lactic  acid.  Whatever  the  acid  may  be,  its  de- 
velopment seems  to  be  local  rather  than  general,  and 
is  apparently  excited  by  catarrhal  influences  rather 
than  by  previous  accumulation  of  acid  in  the  tissues 
and  fluids.  The  acute  manifestation  of  the  disease 
occurring  for  the  most  part  among  young  adults,  or 
during  the  earlier  period  of  middle  age,  there  is  not  the 
same  impairment  of  tissue  as  is  the  case  with  gouty 
patients,  which  may  account  for  the  non-deposition 
of  urate  of  soda ;  or  else  the  specific  character  of  the 
inflammation  being  excited  by  a  different  cause,  and 
not  to  a  prolonged  saturation  of  the  tissues  with  acid 
products,  does  not  lead  to  the  accumulation  and  de- 
posit of  uric  acid  in  the  tissues. 


INDEX 


Acetic  acid,  38. 
Acetonsemia,  98. 
Acetone,  8. 
Acid  albumin,  36. 

fermentation  of  urine,  111. 

Acid  reaction,  liiglily.  Causes  of, 

112. 

,  how  determined,  112. 

of  crastric  jxiice,  179. 

of  urine,  109. 

- —  secretions  formed  from  alka- 
line blood,  21-,  111,  182. 
Acids,  Organic,  8. 
Albnmin,  final  products  of  dises- 

tion  by  gastric  and  pancreatic 

juice,  217. 

,  sero-.  Estimation  of,  145. 

, ,  Separation  of,  in  blood, 

&t. 

, , ,  in  urine,  142. 

, ,  Tests  for,  33. 

Albuminuria,  Causes  producing, 

141. 
— — ,  Temporary,  from  functional 

derangement  of  liver,  214. 
Alcohol,  6. 
Aldehyde,  7. 
Alkali-albumin  (casein),  Test  for, 

36. 

in  milk,  103. 

Alkaline  phosphates  in  urine,  113. 

,  Estimation  of,  135. 

,    Eeduction    of,   in 

scurvy,  292. 
Alkaline  reaction  of  bUe,  193. 

of  blood,  67. 

of  dropsical  fluids,  277. 

of  hydatid  cysts,  231. 

of  pancreatic  juice,  216. 

of  pus,  273. 

of  saliva,  176. 

of  urine,  fl^ed,  113. 

,    how    determined, 

70, 114. 
,  volatUe,  115. 


Alkaloids,    Separation   of,    from 

tissues,  192. 

,  Tests  for,  14. 

AUantoin,  50. 

,  Fluid  of,  279. 

Amides,  9. 
Ammonia,  60. 

,  Formation  of,  in  urine,  115. 

Ammonio-magnesium    phuspliat« 

deposit  in  calculi,  248. 

in  urine,  134. 

Amnii  liquor,  Composition  of,  ^79. 
,  Sugar  in,  at  early  period 

of  gestation,  absent  at  full  term, 

206. 
Amylum,  Tests  for,  9. 
Amyloid   degeneration   (see    Lar- 

daceous),  264. 
Analysis,  15. 
Anazoturia,  109. 
Anderson,  Dr.,  on  leucin  in  urine, 

frequency  of,  169. 
Anti-albumose,  187. 

peptone,  187. 

Antimony,  Poisoning  by,  191,  230. 
Arsenic,  Poisoning  by,  191,  230. 
Ash  (see  Salts). 
Asphyxia,  95. 
Atropine,  51. 
Azoturia,  107. 

Baker,  Morrant,  crystalline  de- 
posit of  calcivun  oxalate  on 
calcidus,  249. 

Baruria,  109. 

Beneke,  on  causes  of  oxaluria,  228. 

Benzoic  acid,  42. 

Bertholet  on  coefficient  of  partage, 
181. 

Bezoar  stones,  Nature  of,  256. 

Bile  acids,  202. 

,  Composition  of,  43,  44. 

,  Physiological  action  of, 

203. 

,  Spectral  analysis  of,  202. 


300 


Clinical  Chemistry. 


Bile  acids,   Spectroscopic  exami- 
nation of,  202. 

,  Tests  for,  163. 

,  Analyses  of,  193. 

,  Characters  of,  194. 

,  Tatty  matters  of,  205. 

in  urine,  Tests  for  pigment 

and  acids,  163. 

jaundice,  195. 

,  mucin,  198. 

,  Physiological  action  of,  193. 

pigments,  199. 

iu  gall  stones,  252. 

,  Nature  of,  199. 

,  Spectral  analysis  of,  200. 

,  Tests  for,  163,  202. 

■ ■  salts,  205. 

Hillary  calculi,  250. 

Bilirubin,    Action    of    osydising 

agents  on  s]pectrum  of,  200. 

■ ,  Decomposition  of,  200. 

,  how  obtained,  199. 

BJood,  Albuminous    constituents 

of,  71,  84. 

,  Clinical  examination  of,  74. 

,  Colouring  mutter  of,  73, 

,  Extractives  of,  87. 

,  Patty  matters  in,  85. 

in  urine,  159. 

,  Reaction  of,  67. 

,  Salts  iu,  93. 

,  Solids  of,  65. 

,  Spectroscopic     examination 

of,  77. 
stains.  Chemical  tests   for, 

83. 

,  Toxic  conditions  of,  94. 

,  Water  of,  65. 

Pone,  Analysis  of,  285. 

,  Chemical     changes     of,    in 

rickets,  288. 
, ,    in    osteomalacia, 

289. 

,  Composition  of,  283. 

,  Morbid  changes  in, 

Brodie,  Sir  Benjamin,  on  calculi, 

formation  of,  238. 

■ , ,  fracture  of,  241. 

Brucine,  51. 

Busk,   Mr.,    on   analyses    of   the 

blood  in  scurvy,  291. 
Butyric  acid,  39. 
ferment,  20. 

Calcareous  degeneration,  272. 
Calcium,  Calculation  of,  287. 

,  Estimation  of,  57. 

in  bones  as  phosphate  and 

carbonate,  283. 


Calcium  in  calculi  as  carbonate, 

249,  254. 

as  oxalate,  249. 

as  phosphate,  248. 

in  fasces,  223. 

in  urine  as  oxalate,  128. 

Calculi,  Biliary  Analysis  of,  253. 

Characters  of,  250. 

,  Formation  of,  251. 

,  gouty  concretions,  257. 

,    miscellaneoiis   concretions, 

259. 

,  pancreatic.  Analysis  of,  254 

iiitestii)al   concretions. 

Enumeration  of,  256. 

,  Prostatic,  257. 

,  renal  and  urinary,  235. 

,  Analysis  of,  246. 

,   Disintegration  of, 

241. 
,  Origin    and    mode 

of  formation  of,  236. 
,  Solvent  treatment 

of,  241. 

,  Salivary,  257. 

Capric  acid,  ^9. 

Caproic  acid,  39. 

Carbohydrates,    Composition  of, 

28. 
Carbolic  acid,  42. 
Carbonate   of   lime   calculi,    249, 

254. 
Carbonic  acid,  40. 

,  Estimation  of,  255,  287. 

Carnin,  50. 
Casein,  36. 
(alkali   albumin)    in    milk, 

103. 

,  Tests  for,  36. 

Cases  of   successful    solution   of 

urinary  calculi,  243. 
Cerebro-spinal  fluid.  Analysis  of, 

277. 
Charles,  Dr.  Cranstoun,  on  mucin 

in  case  of  myxoedema,  270. 
Chemical  composition  of  tissues 

and  fluids,  1. 
Cholestersemia,  97,  205. 
Cholesteric  acid,  42. 
Cholesterin  m  bile,  205. 

in  blood,  85. 

in  chyle  and  lymph,  101. 

in  gall  stones,  251. 

in  ovarian  cysts,  281. 

mistaken  for  lu-ic  acid,  259. 

,  Tests  for,  43. 

Choletelin,  Formation  of,  200. 

in  urine,  116. 

ChoUc  acid,  43. 


Index 


;oi 


Clioliu  (neurin),  +5. 

,  Hoimration  of,  R5. 

Chondi-in,  37. 

Chyle,  Composition  of,  101. 

absorbed  from   jejunum  aiifl 

upper  part  of  ileum,  2U*. 

Chylous  urine,  Anali'scs  of,  165. 

Chyme,  219. 

Clark,  Sir  Andrew,  on  renal  inade- 
qiiacy,  109,  214. 

Co-ellicient  of  partasro,  181. 

Collai,'en,  Decompositiou  of,  269. 

Colloid  defjeueratiou,  268. 

medium  in  calculous  disease, 

237. 

Colostrum,  102. 

Colouring  matters  of  bile,  199. 

of  blood,  73. 

of  urine,  116. 

Composition  of  organic  sub- 
stances, 3. 

Coiipcr,  Poisoninp:  by,  231. 

,  Presence  of,  in  tissues  and 

secretions,  206. 

Corpora  amylacea,  267. 

Corrosive  poisons,  191, 

Curarine,  51. 

Cystin,  Characters  of,  45. 

in  calculi,  247. 

in  uriue,  166. 

Desreneratiou,  products  of,  Cal- 
careous, 272. 

, ,  Colloid,  269. 

, ,  (Corpora  amylacea,  267. 

, ,  Fatty,  261. 

, ,  Hyaline,  266. 

, ,  Lardaceovis,  264. 

, ,  Mucoid,  26-J. 

Deposits  of  cholesterin  mistaken 
for  uric  acid,  2.59. 

Dextrin,  Tests  for,  31. 

Dextrose,  Tests  for,  29. 

Diabetes  insipidus,  107. 

mellitus,  Acetonsemia  in,  99. 

,  Bernard's  view  of,  207. 

,  Blood  in,  98. 

•   ,     Distinguished     from 

glycosuria,  211. 

,  Dr.  Pavy's  view  of,  207. 

■ ,  Estimation  of  sugar  in, 

151,  153,  155,  157. 

■ ,  Increase  of  urinary  flow 

in,  108. 

,  Origin  of,  207. 

-,  sugar  in,  Tests  for,  150. 

Dialysis,  28. 

,    Separation    of    \irca   from 

blood  by  means  of,  87. 


Disintepration  of  calculi,  atl. 
Drafrgoridorf     on     bile    acids    in 

normal  ui'ine,  203. 
Dropsical  fluids.  Analysis  of,  277. 
Drop.sy,  how  caused,  275. 
Dyspepsia,  Acid,  112,  180. 
,  Flatulent,  226. 

Eichwald  on  decomposition  of 
mucin,  281. 

on  peptones  in  pus,  273,  275. 

in  urine,  ll8. 

on  separation  of  mucin,  271. 

Elasticin,  37. 

EUagic  acid,  256. 

Estimation  of  total  nitrogen,  232. 

Ewald  on  liydrochloric  acid  of 
gastric  juice,  182. 

— —  on  pancreatic  secretion,  vari- 
able nature  of,  215. 

on  pUysiological  and  patholo- 
gical fermentations,  21. 

Extractives,  Aqueous  and  al- 
coliolic,  2. 

in  blood,  86. 

in  chyle  and  lymph,  101. 

in  dropsical  fluids,  277,  282. 

in  fasces,  221. 

in  milk,  102. 

Exudations,  dropsical  fluids,  275. 

,  hydatid  cysts,  281. 

,  liquor  amnii  and    allantoic 

fluid,  279. 

,  murbid  pus,  273. 

,  ovarian  cysts,  279. 

,  reual  cysts,  281. 

,  synovia,  279. 

Feeces,  Analyses  of  healthy,  221. 

,  Composition  of,  221. 

,   Examination  of  in  disease, 

224. 

,  Meconium  in,  223. 

,  Stercorin  and  excretin,  221. 

Fats,  neutral.  Composition  of,  31. 

Fatty  acids,  37. 

degeneration.  Acute,  of  liver, 

261. 

• — -,  Infiltration  of,  260. 

,  Nature  of,  260. 

— — ,  Separation  of  fatty  mat- 
ters in,  263. 

- — matters,  Digestion  of,  194, 
216. 

,  Estimation  of,  85. 

in  bile,  205. 

in  blood,  85. 

in  bone,  285. 

in  chyle  and  lymph,  101. 


302 


Clinical  Chemistry. 


Fatty  matters  in  fseces,  224. 

in  milk,  102. 

in  pus,  273. 

in  urine,  165. 

,  Separation  of,  263. 

Feltz  and  Eitter  on  ammoniacal 
decomposition  of  nrine,  116. 

Fen  wick.  Dr.,  on  sulpho-cyanate 
of  potassium,  pathological  im- 
port of,  57. 

Fermentations,  Nature  of,  17. 

Ferments,  Lactic  acid,  225. 

. ,  Organised,  19. 

,  Pepsin,  184. 

,  Ptyalin,  175. 

■ ,  Trypsin,  216. 

,  Unorganised  or  soluble,  20. 

,  Urea  fermentation,  115. 

,  Teast,  153. 

Fever,  Chemical  pathology  of,  18. 

Fibrin,  Concretions  of,  247,  256. 

,  Estimation  of  in  blood,  71. 

ferment,  35,  72. 

in  chyle  and  lymph,  101. 

in  urine,  147. 

,  Tests  for,  36. 

Fibrinogen  in  chyle  andlymph,101. 

m  dropsical  fluids,  277. 

,  presence  in  blood,  72. 

■ ,  Tests  for,  34. 

Fibrino-plastic,  34,  72,  84. 

Fibrinous  concretions,  247,  255. 

Flatulent  dyspepsia,  226. 

Flatus,  Nature  of,  225. 

Flint,  Dr.,  on  cholestersemia,  97, 
205. 

on  stercorin,  221, 

Formic  acid,  38. 

Frerichs  on  bile  acids,  injection 
of,  204. 

on  peptones  in  urine,  148. 

Fusible  calculus.  Analysis  of,  248. 

Gall  stones,  Analysis  of,  253. 

,  Formation  of,  251. 

Gamgee,    Professor,    on   mucoid 

degeneration,  nature  of,  272. 
Garrod,  Dr.,  on  gout,  views  re- 
garding, 296. 
on  potash,  diminution  of,  in 

scurvy,  291. 
■ on  sodium  urate  deposit  on 

joints,  258. 

on  uric  acid  in  blood,  123. 

Gases  in  stomach  and  intestines. 

Nature  of,  224. 
Gaskell,  Dr.,  on  dilute  acid  and 

alkaline  solutions,  influence  on 

circulation,  23,  69. 


Gelatin,  37. 

Gerhardt  on  peptones  in  urine, 
148. 

Globulin,  Tests  for,  33. 

Glucose  in  blood,  88. 

in  urine.  Detection  and  esti- 
mation of,  150. 

,  Tests  for,  29. 

Glycerin-phosphoric  acid  in  fatty 
degeneration  of  brain,  262. 

,  Tests  for,  .32. 

Glycocholic  acid,  45. 

Glycocin,  43. 

Glycogen,  Tests  for,  31. 

Glycogenic  function  of  liver, 
206. 

GlycoUic  acid,  41. 

Gould,  A.  Pearce,  on  calculus  con- 
taining purulent  fluid,  242. 

Gout,  Diminished  alkalinity  of 
blood  in,  295. 

,     relation     to    scurvy     and 

rheumatism,  ,290. 

,    uric    acid    not    necessarily 

formed  in  excess,  296. 

Gouty  concretions.  Tophi,  257. 

Gowers,  Dr. ,  on  method  of  estima- 
ting haemoglobin,  76. 

Guanin,  60. 

Hsematin,  81. 

Hsematinuria  from  functional  de- 
rangement of  liver,  214. 

,  Nature  of,  161. 

Hsematogenous  jaundice,  196. 

Hoematoidin,  83,  201. 

Hasmatopopphyrin,  82. 

Hsematuria,  160. 

HEemic  calculi,  287. 

Hasmin,  82. 

Hsemochromogen,  82. 

Haemoglobin,  Estimation  of,  75. 

,  Tests  for,  35. 

Hammarsten  on  digestion  of  milt, 
186. 

Hay  craft.  Dr.,  on  method  of  sepa 
rating  urea  from  blood,  87. 

Hemi-albumose  (Meissner's  a  pep- 
tone), 187. 

glutin,  269. 

-peptone,  187. 

Heninger,  on  peptones,  composi- 
tion of,  187. 

Heptogenous  jaundice,  195. 

Hippocrates'  views  regarding  cal- 
culi, 235. 

Hippuric  acid.  Character  of,  46. 

,  in  urine.  Separation  of, 

139. 


Index. 


303 


HofTmnnn     on     feeding    animals 

with  iicid  salts,  efTects  of,  23. 
Hofmeister  on   decomposition  of 

collason,  269. 

ou  liictosuria,  102. 

ou  peptoues  iu  urine,  119. 

Holmes,    Air.    T.,    ou    punctured 

wound  of  ureter,  278. 
Hoppe  Seyler,  on  analyses  of  bile, 

193. 
on  composition  of  bajmo- 

jrlobin,  80. 
Hyaliue  dcj^encration,  266. 
Hydatid   cysts,   Composition  of, 

281. 
Hydrate  of  albuminate  (peptone), 

187. 
Hydrocarbon  radicals,  5. 
Hydrocarbons,   4. 

of  the  aromatic  series,  6. 

Hydrochloric  acid,  54-. 

,  Estimation  of,  in  urine, 

137. 

in  gastric  juice,  180. 

Hydrofluoric  acid,  55. 

,  Estimation  of,  in  bones, 

287. 
Hydruria  from  increased  or  dimin- 
ished mctamor[ihosis,  107. 
Hypoxauthin  in  blood,  93. 

in  urine.  Separation  of,  168. 

,  Tests  for,  50. 

Indican  in  disease  of  pancreas, 
218 

in  obstruction  of  small  intes- 
tines, 218. 

in  urine,  117. 

,  Nature  of,  53. 

Indigo,  bow  formed  in  sweat  and 
urine,  218. 

in  calculi,  247. 

test  for  sugar,  154. 

Indol,  53. 

Inorganic  constituents.  Chemical 
importance  of,  22. 

,  conditions  in  which  they 

exist  iu  the  body.  26. 

,  Distribution  of,  25. 

Inosite,  29. 

Intestinal  concretions,  255. 

digestion,  219. 

,  Gases  in,  224. 

Intestine,  Large,  220. 

,  small,  Contents  of,  219. 

Invert  sugar  from  cane  sugar 
in  intestinal  digestion,  219. 

,  Tests  for,  29. 

Iron,  65. 


JafT6'8  reBcarclies  into  nature  of 

bile  pigments,  200. 
Jaundice,  Hiomatogonous,  196. 

,  Heptogeuous,  195. 

Johnson,    Dr.   George,   on  gouty 

kidney,  297. 
,  ,  on  picric  acid  test  for 

albumin,  14.3. 
,  ,  on for 

sugar,  155. 
,  ,  on  saccharometer,  157, 

158. 
Jones,  Dr.    Bence,  on  acidity  of 

urine    after    alkaline  bicarbon- 

ates.  111,  24-1. 
, ,  on  albumin  in  urine  in 

case  of  osteomalacia,  147. 

, ,  on  cystin,  166. 

, ,  on  xanthin,  167. 

Klein  on  hyaline  degeneration,  267. 

KoUiker  on  corpora  amylacea,  267. 

Kreatin,  Separation  of,  from  blood 
or  muscles,  92. 

,  Tests  for,  48. 

Kreixtinin,  48. 
—  in  urine,  140. 

Krusenstern  on  injection  of  choles- 
terin  into  veins  of  dogs,  effects 
of,  97. 

Kuhne,  Prof.,  on  bile  acids,  action 
on  hoemoglobiu,  2i4. 

, ,  on  hippuric  acid,  where 

formed,  139. 

, ,  on  peptones,  classifica- 
tion of,  187. 

Lactic  acid,  41. 

,  Consequences  of  excess 

of,  227—229. 

ferment,  20. 

in  intestines,  225. 

in  rickets,  2~8. 

in  scurvy,  294. 

Lactose  in  milk,  103. 

in  urine,  102. 

,  Tests  for,  30. 

Lmvulose  (invert  sugar).  Charac- 
ters of,  29. 

Lardaceiu,  Nature  of,  265. 

,  Separation  of,  266. 

,  Tests  for,  37. 

Lardaceous  degeneration,  26-t. 

Lead,  Separation  of,  from  solid 
tissues,  231. 

in  urine,  172. 

Lecithin,  Characters  of,  47. 

in  blood,  86. 


304 


Clinical  Chemistry. 


Lecithin   in    lymph    and    chyle, 

101. 
Legg,  Dr.  "Wictham,  on  action  of 

hile  acids  on  heart,  203. 
, ,  on  bile  acids,  how  de- 
rived, 203. 
, ,  on  hile  and  its  relation 

to  the  formation  of  glycogen, 

195. 
, ,on  absence  of  pigment  in 

urine  after  injection  of  bile  acids, 

204. 
Leucic  acid,  41. 
Leucin,  Characters  of,  45. 

in  urine.  Separation  of,  168. 

result  of  pancreatic  digestion, 

217. 
Lime,  Estimation  of,  58. 
Lithsemia,  211. 
Liver,    Functional    derangement 

of,  206. 
Liversidge  on  starch  ferment  of 

pancreatic  juice,  216. 
Loscar  on  feeding  animals  with 

acids,  effect  of,  23,  68. 
Lymph,  101. 

Mackenzie,  Dr.  Stephen,  on  case 

of  chylous  urine,  164. 
, ,  on  hyaline  degeneration, 

266. 
MacMunn,      Dr.,     on     colouring 

matter  of  urine,  116. 
, of  bile ;    spectrum 

of  Pettenkoffer's  test,  202. 
,   on   spectrum   of    dropsical 

fluid,  277. 
,    of     ovarian    fluids, 

282. 
JMagnesia,  Calculation  of,  286. 

,  Estimation  of,  59. 

, in  bones,  283. 

, in  calculi,  248. 

, ,  in  faeces,  223. 

Mahomet,    Dr.,     on    pre-albumi- 

nuric  stage  of  Bright's  disease, 

141. 
Maly,  E.,  on  acidity  of  urine,  how 

caused,  183. 
,    on   formation   of     acid   in 

gastric  juice,  24,  54. 
,  on  oxydation   of    bilirubin, 

product  of,  200. 
Marrow  of  bone.  Composition  of, 

284. 
Maxwell,  Dr.,  on  case  of  puerperal 

albuminuria,  urea  in,  120. 
Meat,  Eresh,  why  antiscorbutic, 

293. 


Meconic  acid  and  sulpho-cyanate 
of  potassium,  57. 

,  importance  of 

distinguishing  between  them  in 
medico-legal  inquiries,  175. 

test  for  in  opium  poison- 
ing, 192. 

Meconium,  223. 

Melanin,  117. 

Mercury,  Detection  of,  177. 

Metabolism  increased  tissue  in 
fever,  18. 

in  states  of  constitu- 
tional disturbance,  213. 

Metalbumin  in  ovarian  cyst,  281. 

Methsemoglobin,  Characters  of 
78. 

in  urine,  162. 

Meissner  on  nuclein  in  pus  cells, 
273. 

Milk,  Composition  of,  101. 

,  Digestion  of,  102,  186. 

sugar  in  milk,  103. 

• ■  — —  in  urine,  102. 

,  Tests  for,  30. 

Moore,  Dr.  Norman,  on  fossil 
bones,  285. 

Morbid  exudations,  dropsical 
fluids,  275. 

,  hydatid  cysts,  281. 

,  hydro  -  nephrotic  cysts, 

281. 

,  liquor  amnii  and  allan- 
toic fluid,  279. 

,  ovarian  cysts,  279. 

,  pus,  273. 

,  synovia,  279. 

Morochowitz  on  mucin  and  col- 
lagen as  embryonic  state  of 
bones,  289. 

Morphia,  Detection  of,  in  vomit, 
192. 

in  tissues,  232. 

,  Tests  for,  51. 

Mucin  in  bile,  198. 

in    embryonic    condition     of 

connective  tissue,  268,  and  bone, 
289. 

in  mucoid  degeneration,  270. 

in  saliva,  175. 

,  relation  to  paralbumin,  280. 

,  Tests  for,  36. 

Mucoid  degeneration.  Changes  in, 
268. 

,  Professor  Gamgee's  view 

of,  272. 

Mucus  distinguished  from  pus, 
171,  273. 

in  urine,  170. 


Index. 


305 


Murcbisou,      Dr.      Cluirles,      on 

amouut  of  bile,  19 1. 
, ,  ou  doctriue  of  litlice- 

mia,  212. 
,  ,    on    fluid    of  hydatid 

cysts,  281. 
Murexide   reaction,   49,  127,   246, 

•IVi. 
Murray,  Dr.,  Newcastle,  on  soft- 
water  in  treatment  of  calculi, 

245. 
Muscle,     Separation    of    kreatin 

from,  92. 
Myeloplaxes,  284. 
Myosin,  Test  for,  35. 
Myxoedema,  Nature  of,  270. 
Myiomata,  Nature  of,  271. 

Naunym   on  bile  acids  in  normal 

urine,  20 J. 
Neal,  Dr.,  on  fresh  meat  in  scurvy, 

292. 
Neurin  (cholin),  45. 
Nitric  acid,  peculiar  re-action  with 

urates,  127. 
test    for   albumin   in 

urine,  143. 
Nitrogen,    Estimation    of    (soda 

lime  process),  232. 
Nitrogenous  compounds,  3. 

,  Enumeratioa  of,  33,  43. 

Non-nitrogenous  compounds,  3. 

,  Enumeration  of,  28,  87. 

Nuclein,  273. 

Oleic  acid,  39. 

,     Separation    of,     from 

stearic  acid,  264. 

Oliver,  Dr.,  on  indigo-carmine  test 
for  glucose,  154. 

Opium,  192. 

Ord,  Dr.  W.  M.,  on  biliary  calculi, 
formation  of,  251. 

, ,  on  disintegration  of  cal- 
culi, 24]. 

, ,  on  indigo  calculus,  247. 

,  ,  on   molecular   coales- 
cence, 27. 

, ,  on  myxojdema,  270. 

Organic  acids,  Separation  of,  from 
mineral,  281. 

Organised  ferments,  19. 

by  yeast,  153. 

,  lactic  acid  fermentation, 

225. 

,  urea  fermentation,  115. 

Osteomalacia,  Albumin  of  urine 
in,  187. 

■ ,  nature  of  changes,  289. 

U 


Osteomalacia,  pj-obable  relation  to 

myxcedeina,  289. 
Oxalic  acid  as  oxalate  of  lime  in 

urine,  128. 

,  Characters  of,  41. 

,  Poisoning  by,  190. 

Ovarian  cysts,  Analvsis  of,  282. 

,  Contents  of,  279. 

Oxydatiou  in  fevers,  18. 

,  Nature  of,  17. 

Oxygenated  blood ,  Limited  supply 

of,  co-use  of  diabetes,  207. 

Pages  injection  of  cholesterin 
into  veins  of  animals,  effects  of, 
97. 

Palmitic  acid,  39. 

. ,    Separation     of,     from 

oleic  acid,  2(54. 

Palmitiu,  Tests  for,  32. 

Pancreas,  Disease  of,  218. 

, ,  Increase  of  indican  in 

lu-ine  due  to,  218. 

, ,  relation  to  diabetes  and 

glycosm-ia,  211,  218. 

Pancreatic  calculi.  Analysis  of,  254. 

iui  e.  Analysis  of,  unre- 
liable, 215. 

fat  ferment,  20-216. 

,  Ferments  of,  216. 

,  joint  action  with  gastric 

juice  oil  proteids,  217. 

,  Reaction  of,  216. 

Paracelsus,  Calculi  first  analysed 
by,  236. 

Poraglobulin  in  urine,  147. 

,  Separation  of,  in  blood,  84. 

,  Tests  for,  34. 

Paralbumin  in  ovarian  cysts,  280. 

Parkes,  Professor,  on  acidity  of 
lu-ine  after  alkaline  bicarbo- 
nates.  111. 

, ,  on  chemical  circulation 

in  body,  22. 

, ,  on  entrance  and  exit  of 

nitrogen,  23-4. 

Pathological  and  physiological  fer- 
mentations, 17. 

Pavy,  Dr.,  on  separation  of 
glucose  from  blood,  88. 

,    on    views    with    regard    to 

the  natiu-e  of  diabetes,  207. 

Pepsin  ferment,  20. 

in  gastric  juice,  184. 

Peptones,  36. 

in  pu-i,  273. 

in  urine,  1-48. 

of  pancreatic  juice,  217. 

of  the  gastric  juice,  186. 


3o6 


Clinical  Chemistry. 


Phenol  (carbolic  acid),  42. 
Phosphatic  diabetes,  107. 
Phosphoric  acid,  55. 

,  Estimation  of,  131. 

Picric  acid  test  for  albumin,  143. 

for  peptones,  148, 186. 

-. for  sugar,  155. 

Planer    on  analysis  of  gases   of 

stomach  and  intestines,  225. 
Poisons,  antimony,  231. 

,  arsenic,  230. 

,  carbolic  acid,  191. 

,  caustic  alkalies,  191. 

,  Corrosive,  191. 

,  Detection  of,  in  tissues  and 

viscera,  229. 

,  ,  in  vomit,  190. 

,  hydrocyanic  acid,  191. 

,  Lead,  172. 

,  meconic  acid,  192. 

,  mercury,  177. 

■ ,  Metallic  irritant,  191. 

,  morphia,  192,  232. 

,  opium,  192. 

,  oxalic  acid,  190. 

,  phosphorus,  191. 

,  strychnine,  192,  232. 

,  sulphuric  acid,  191. 

,  Veg-eto-alkaloid,  192. 

■ -,  Volatile,  191. 

Polarimeter,  158, 
Polyuria,  107. 
Potash,  60. 

,  Estimation  of,  62. 

Propionic  acid,  39. 
Prostatic  calculi,  257. 
Proteids,  Constitution  of,  14. 

,  Digestion  of,  186,  217, 

,  General  character  of,  33. 

in  blood,  71,  84. 

in  chyle  and  lymph,  101. 

in  milk,  102. 

in  pancreatic  juice,  215. 

in  urine,  140. 

Ptoamines,  52. 
Ptyalin  in  saliva,  175. 

,  nature  of  fernient,  20. 

Pus,  Analysis  of,  273. 

in  urine,  170. 

Pyo-cyanin  and  pyo-xanthin,  274. 

Quekett,  Professor,  on  calcium 
oxalate  in  renal  cell,  238. 

Quincke  on  variations  of  hsemo- 
globin  in  disease,  74. 

Eainey,  Professor,  on  molecular 

coalescence,  26. 
Ee-action  of  bile,  193. 


Ee-action  of  blood,  67. 

of  dropsical  fluids,  277. 

of  gastric  juice,  179. 

of  hydatid  cysts,  281. 

of  pancreatic  juice,  216. 

of  pus,  273. 

of  saliva,  176. 

of  urine,  101. 

Eees,  Dr.  Owen,   on  ammoniacal 

reaction    of   urine.  Causes    of, 

119. 

• ,  — — ,  on  gouty  catarrh,  237. 

Eenal  cyst,  Contents  of,  281. 

inadequacy,  109 — ^214. 

Eheumatism,    Discharge  of  acid 

in,  298. 
,  relation  to  gout  and  scurvy, 

290. 
Eichet     on    acidity    of    gastric 

.iuice,  180. 
Eickets,  hsamorrhagic  form,  pro- 
bably related  to  scurvy,  289. 

,  Nature  of  changes  in,  288. 

,  Views  with  regard  to,  289. 

Ringer,      Dr.,      on       potassium, 

sodium,  and    ammonium  salts, 

action  of,  23,  26. 
Roberts,  Dr.  W.,  on  fermentation 

test  for  sugar,  153. 
Role    of    inorganic    constituents, 

22. 

Saccharose,  Tests  for,  30. 
Salts  in  bile,  205. 

in  blood,  93. 

•  in  bone,  286. 

in  chyle  and  lymph,  101. 

in  faeces,  223. 

in  gastric  juice,  179. 

in  milk,  102. 

in  pancreatic  juice,  215. 

in  pus,  975. 

■  in  saliva,  175. 

in  urine,  127, 128,  131, 136, 137. 

,  Soluble  and  insoluble,  2. 

,  To  estimate,  94. 

Saliva,  Composition  of,  175. 

,  Detection  of  mercury  in7177. 

,  quantities  secreted,  176. 

,  Varieties  of,  173. 

Salivary  calculi.  Composition  of, 

256. 
Salivation,  176. 
Saponiflable  fats.  Characters  of,  31. 

• ,  Estimation  of,  86. 

in  blood,  85. 

in  chyle  and  lymph,  101. 

in  fatty  degeneration,  263. 

Sarcosin,  45. 


Index. 


307 


Scheele,  Uric  acid  discovered  by, 
236. 

Scherer  on  discovery  of  inu-al- 
bumin,  2S0. 

on  separation  of  mucin,  271. 

Scheteli^  on  paralbumin  in  reual 
cysts,  281. 

Schultzen  and  Eiess  on  peptones 
in  urine,  1-lS, 

Scurvy,  Diminution  of  alkaline 
phosphates  in,  2'J2. 

,  relation  to  gout  and  rheu- 
matism, 290. 

,  views  regarding  changes  of 

blood,  291. 

,  vphy  fresh  meat  and  vege- 
tables are  anti-scorbutic,  293. 

Seemou,  Dr.,  on  urine  in  riclvots, 
288. 

Semi-glutin,  2o9. 

Sero-iuteiu,  Sijactrum  of,  277. 

Serum,  Blood,  84. 

Silica,  6-t. 

in  bile,  206. 

in  bone,  285. 

in  foeces,  223. 

Sodium  salts,  Estimation  of,  62, 

in  bile,  205. 

in  blood,  94. 

Solids,  Estimation  of,  by  evapora- 
tion, 06. 

,    ,    by    specific    gravity, 

106. 

Soluble  ferments,  19. 

Specific  gravity  of  bile,  193. 

of  blood,  66. 

of  dropsical  fluids,  277. 

of  hydatid  cysts,  2S1. 

of  ovarian  cysts,  279. 

of  urine,  105. 

Spectroscopic  characters  of  chole- 
telin  in  lu'ine,  116. 

of  dropsical  fluid,  277. 

of  htemoglobin   and  its 

compounds,  76. 

— of  ovarian  cysts,  280. 

of  osydised  bile  pigments, 

200. 

of  Petteukotfer's  test  for 

bile  acids,  203. 

Staedeler  on  separation  of  mucin, 
271. 

Starch,  Tests  for,  30. 

Stearic  acid,  39. 

,  Separation  of,  from  oleic 

acid,  264. 

Stearin,  Tests  for,  32. 

Sterner  on  action  of  bile  acids  on 
heart,  204. 


Strychnine,  Detection  of,  in 
tissues,  232. 

, ,  in  vomit,  192. 

,  Tests  for,  ,51. 

Succinic  acid,  42. 
Siiitar  (»te  Glucose). 
Sulpho-cyauate  of  potassium,  57. 

in  saliva,  175. 

Sulphur,  unoxydisediu  urine,  137. 
Sulphuric  acid,  56. 

■.  Kstimation  of,  137. 

Synovia,  279. 
Synthesis,  15. 
Syntoniu,  36. 

Taijpeiner  on  absorption  of  bile 
at^ids,  203. 

Taurin,  41. 

Taurocholic  acid,  44. 

Tossier,  Dr.,  on  i)hosphatic  dia- 
betes, 107. 

Tiil'enbach  on  glycosuria  pro- 
duced by  artificial  respiration, 
209. 

Topki,  gouty  concretions,  257. 

Tyrosi-:,  Character  of,  46. 

in  urine.  Separation  of,  169, 

UriBmia,  95. 

Urates  in  calculi,  249. 

in  gouty  tophi,  257. 

in  urine,  127. 

Urea,  Derivation  of,  12. 

,  Estimation  of,  in  iirine,  122. 

ferment,  20. 

,  Relation  of,  to  temperature, 

19. 

,  Separation  of,  in  blood,  87. 

,  Test  for,  47. 

•,  Variation  of,  in  disease,  118. 

Uric  acid  calculi,  246. 

,  Clinical  significance  of 

deposits  of,  125. 

,  Estimation  of,  127. 

,  Gouty    concretions   of, 

257. 

in  blood,  93. 

in  urine,  123. 

,  Pathological   relations 

of,  123. 

■ -,  Test  for,  48. 

Urine,  Abnormal  constituents  of, 

140. 
,   Alkaline    and  earthy  phos- 

Ijhates  in,  131. 
and  bile.   Test  for  pigment 

and  acids  in,  163. 

,  Blood  as  hoematuria  in,  160. 

, as  hsematiimria  in,  161. 


3o8 


Cl  I  NIC  a  l   C hem  is  TR  J ', 


Urine,  CaJoiuxn  oxalate  iu,  128. 

,  CbloriJes  iu,  136. 

,  chyle  in.  Analyses  of,  16j. 

,  Clinical  examination  of,  IW. 

,  Cystiu  in,  166. 

,  Estimutiou  of  Lydrocbloric 

ucid  iu,  137. 
,  of  phosphoric  acid  in, 

135. 

, of  Bulpliiiric  acid  in,  138. 

,  Pibriu  clots  iu,  1+7. 

,  hippuric  acid  in,  Separation 

of,  lay. 

,  Hyjjoxanthin  in,  168. 

,  Kreutinin  in,  140. 

,  \etiA,  Detection  of,  in,  172. 

— ,  Louciu  in,  168. 

,  MucuH  and  pus  iu.  170. 

,  Piiraslolniliii  iu,  1+7. 

,  peptones  in,    To  Beparntc, 

\Mi. 

piemcut,  116. 

,  Pro-peptoae  in,  147. 

rv-actiou,  K<3. 

,  sero-olbumin  in,  TesLt  for, 

,  Eittimation  of,  145. 

,  Spociflc  irmvitr  of,  106. 

,  Su>{nr-t«iit«  (or,  150. 

, ,  Ettinuttiou  of,  by  copper, 

m. 

, , ,  by  fcrmeutAtiou, 

153. 
,    ,    ,    by    JohoBon'fl 

Mtocbaromoter,  1S5. 
,  , ,   br    poUrimetry, 

1.^. 

,  SulpbatM  in,  137. 

,  TmU  for  blood  in,  162. 

.TyixMiu  in,  ItiS. 

,  ur«*  in,  Eniiniation  of,  122. 

,  ——,   vanAtioux   in   disease, 

118. 


Urine.  Variation  in  reaction  of, 
in  disease,  112. 

,  Xauthin  iu,  167. 

Urobilin,  Formation  of,  200. 

iu  urine,  117. 

Urostealith,  217. 

Valeric  acid,  39. 

Vaso-niotor  i>aralysis  in  diabetes, 
209. 

^— may  be  induced  by  dim- 
inished alkaline  reaction  ot 
blood,  211. 

Vegretables,  Fresh,  why  anti- 
scorbutic. 293. 

Vesreto-alkoloids,  Separation  of,' 
from  tissues,  231. 

,  Tests  for,  51. 

Voit.uitroKeu,  Estimation  of,  232. 

Volatile  poisons,  Dotoctiou  of,  IHl. 

Vomited  matters,  Detection  of 
poisons  in,  l!>0. 

,      Determination       of 

lunoant  and  nature  of  acid  iu, 
188. 

Williams,   Dr.    John,    on    liquor 

ainuii  of  diabetic  patient,  2(.M>. 
,   ,    on     reaction    of   sul- 

jiburic    acid    and    iodine    with 

lardAceiu,  266. 
, ,  on  venesection  in  cost" 

of  puerjKsral  albuminuria,  97. 

Xanthin  calculi.  247. 

,  ChanictiT  ..f,  50. 

in  urine,  167. 

Xautboprotoic  roaction  absent  in 

true  peptones,  1^7. 
of  proteids  geueruUy, 

S3. 

Yout  torment,  20. 


CAA8ELL  AVDOOUPAVr,  UMITKD,  BKLLE  SAUVAOt:  WORKS,  LONDON,  K  C. 


QP514 
Ralfe 
Clinical  chemistry 


R13 


ri 


4 


